Author Archives: Shelby Doyle

‘Transitioning Cambodia’ Photos Show Vanishing Worlds Behind Rapid Development


Until just a few years ago, Boeung Kak Lake in the capital city of Phnom Penh was a prime tourist location and home to thousands of Cambodians. Today, it lies under the sand.

In 2007, a company owned by well-connected Cambodians received a lease to develop the land around the lake. Just a year after it took control, the company started pumping the landmark full of sand, making way for a high-end building project. Thousands of people wereforcibly evicted in the process.

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A resident of Boeung Kak rows a wooden boat against a storm moving in over Phnom Penh on July 7, 2011. The new buildings of the Council of Ministers and the office of the prime minister can be seen in the background.

The upheaval in Phnom Penh is one of the subjects of the forthcoming photography book Transitioning Cambodia, a collaboration between photojournalist Nicolas Axelrod, journalist Denise Hruby and designer Fani Llaurado. The book covers modern development in Cambodia and the effects on its society and landscape.

“For the hundreds of families that were violently evicted from their homes in the city center, development meant that they were relocated to barren plots of land. Schools, health-care centers, markets or any income opportunity were out of reach,” Hruby writes in an article about the book for the Asian Correspondent. “The ones who fought for their land were violently suppressed, driven out of their homes with tear gas and water canons.”

Axelrod has been documenting the rapid pace of development in Cambodia and its impact on the country since 2008. After covering the situation in Boeung Kak, he started photographing other Cambodian communities facing eviction, as well as the emerging middle class who moved in to take their place.

“It’s a phase of Cambodia that we will never see again,” Axelrod told Voice of America Khmer. “It’s impressive how quickly the middle class has grown and there is so much more wealth than before. But what worries me and what I am scared of is that a lot of people have been left out in this change,” he said.

Take a look at a selection of Axelrod’s work below, and go to the Transitioning Cambodia crowdfunding campaign to support the book.

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A worker dismantles a house on Boeung Kak, Phnom Penh, on Aug. 23, 2010. Residents had the option of accepting 8,500 dollars in compensation or receive 500 dollars to relocate to housing provided by the developers on the outskirts of the capital.

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Vin Thy (center) and Chanty (center right) sit in front of their corrugated iron homes in the center of Phnom Penh on March 3, 2009. Their community is slated for a second eviction. The first one saw them move out of their homes in Borei Keila and relocated to a nearby community; their pending eviction will send them to live on the outskirts of the capital.

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An elderly resident of what is known as the ‘Green Buildings’ in Phnom Penh packs her family’s belongings during an eviction on March 3, 2009. The community, made up mostly of families with at least one member affected by HIV, was relocated to corrugated iron sheds in the outskirts of Phnom Penh, with no access to jobs, running water or adequate health care.

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A child plays in muddy water that is spraying out of a broken pipe in Phnom Penh on March 27, 2009. The pipes are pumping sand into a natural lake in Borei Reakreay community. The community was evicted from their homes in mid-2009 to make way for residential complexes.

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Residents flee a bulldozer as it charges into the rubble of destroyed homes during the forced eviction of Dey Krahorm, Phnom Penh, on Jan. 24, 2009. The community of Dey Krahorm in central Phnom Penh was largely made up of artists and musicians. The eviction saw residents relocated to the outskirts of Phnom Penh.

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Camko City, an urban development project three kilometers north of central Phnom Penh, pictured on Jul. 27, 2012. The high-rise buildings and town houses in the satellite city were largely built on land reclaimed from natural lakes.

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Salespeople talk on the phone during an expo about Cambodia on Koh Pich, or Diamond Island, on March 30, 2014. Satellite cities have been developed all around Phnom Penh, offering kit houses in vast residential complexes. Koh Pich was once home to a community of farmers, called Sambok Chap, who were evicted in 2006.

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A group of women look at fried chicken on display at Aeon Mall on Jun. 30, 2014. Aeon Mall is Cambodia’s first mega-mall. The inauguration was attended by Cambodian Prime Minister Hun Sen and groups of residents from various economic backgrounds were trucked in to attend the event.

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Kunthea and her son Panha (right) travel in a tuk-tuk with her cousin in central Phnom Penh on June 5, 2014. Kunthea is a single mother, working as a cleaner for four different expat families.

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Roza preforms at his friend Sam’s birthday party in Phnom Penh on Nov. 30, 2013. Sam is the lead singer of ‘No Forever,’ the first post-hardcore metal band in Cambodia. Along with her band members, she is pushing alternative music in Cambodia.

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A model poses for a fashion shoot in a boutique hotel in Phnom Penh on Feb. 10, 2012. In 2009, fashion became a trendy investment in Cambodia, with high-end labels starting to become available in the capital. In 2011, Cambodia hosted its first annual fashion week.

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Monks get ready on day four of a 10-day human rights march into Phnom Penh on National Road 6, Kampong Thom, on Dec. 4, 2013. After Cambodia’s general elections in July 2013, groups of monks took an active role in politics and promoting human rights.

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Radio station owner Mam Sonando (not pictured) and his supporters clash with riot police during a demonstration in Phnom Penh on Jan. 27, 2014, demanding the government expand his radio’s reach and allow him to open a TV station. Television stations are largely controlled by the state, though foreign newspapers and some radio stations are allowed to operate independently.

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Crowds gather in front of the Royal Palace in Phnom Penh to pay their respects to King Father Norodom Sihanouk on Oct. 21, 2012, after he passed away on Oct. 15. The death of the late King Father marked the turning of an era, as he had overseen Cambodia since the country’s independence from France in 1953.

Phnom Penh’s imperilled architectural heritage

26 January 2015
© Lauren Crothers, dpa
Phnom Penh’s colonial architecture – © Lauren Crothers, dpa

Phnom Penh (dpa) – The former Police Commissariat in Phnom Penh, a proud colonial structure when first built in 1927-31, has seen better days.

Its distinctive yellow plasterwork is pockmarked, filthy and peeling. Trees and shrubs grow unchecked across the grounds, poking through windows, even sprouting from the four-storey roof.

Just across the street stands the imposing, buttery-gold post office, built in 1895 but now restored, in daily use, and commanding the centre of the old French quarter.

The two buildings show the contrasting fates that can await the colonial heritage buildings of Cambodia’s capital, built during the heyday of the French protectorate, but now often derelict and coming under economic pressure for the prime real estate they occupy.

Some can be restored to profitability as high-end venues, said Philippe Delanghe, a culture specialist in UNESCO’s culture unit.

He cited the Hotel le Royal, a favourite haunt of A-list visitors from its opening in 1929, and then of journalists covering the war in the 1970s, recently restored to its former glory by hotel operator Raffles into one of the city’s most desirable addresses.

Another success story is the Van restaurant near the river, built to house the Indochina Bank in the mid 19th Century, restored by the prosperous Van family a few years ago and now considered one of the best restaurants in town.

Beyond the hospitality sector, there is also a market for prestigious official property.

The old post office building now houses the Ministry of Posts and Telecommunications, while another French-built edifice has been repurposed as the British Ambassador’s residence.

And appropriately enough, the offices of the United Nation’s cultural arm UNESCO are in a pristine late 19th-century villa built in the Sino-Khmer colonial style, with a pillared, two-storey facade.

But the market is limited for such high-profile restorations, as the current owners of The Mansion are experiencing.

Built as the private residence of a wealthy Cambodian trader in French protectorate style between 1910 and 1920, The Mansion is struggling to find a buyer despite its prime location.

It was abandoned in the 1975 fall of Phnom Penh, then occupied between 1979 and 1989 by the Vietnamese army after the defeat of the Khmer Rouge.

The current owners, who run the Foreign Correspondents’ Club behind it, hold cultural events there, imbued with a sense of history by the once-golden walls now pockmarked by bullets, damp and mould.

The charm is not to all tastes. A “for sale” sign has hung on the outside wall for several months now, but real-estate firm CBRE has had few serious enquiries about the “unique colonial building.”

“A lot of people have been interested and we have had a few offers,” from both Cambodians and foreigners, but none for the 3.5-million-dollar asking price, she said.

“The price for the mansion is higher than the normal property but we can only market to a limited group of people,” said Thida Ann, an associate director at CBRE Cambodia.

If the cost proves too high, The Mansion may not be safe from the wrecking ball, despite its classified status with the Ministry of Land Management and Urban Planning.

In principle, a 1996 law says any building “proposed for classification or classified” may not be altered without authorization.

But in practice there is “nothing strictly enforced” when it comes to French heritage buildings, UNESCO’s Delanghe said. “There is no real preservation,” he told dpa.

Many potentially classifiable buildings have been demolished to develop the high-value land they occupied.

The distinctive Bridge Tower House, built as a French administration building in 1890, was razed in 2012 despite opposition from preservationists, including UNESCO.

A modern, colourful auto shop now sits in its place, to the consternation of activists who say the owner had committed to rebuilding in the same style.

“It’s not really expensive if you want to restore,” says Sylvain Ulisse, a project manager at the Heritage Mission, a joint awareness-raising initiative by the French embassy and the government.

“The main problem is that the cost of the land is so high that it’s really difficult to have the idea to renovate, because you think: ‘I can have a high building, and I will make more money on it.'”

“When they knock down and build high, there is more value,” said Sung Bonna, chief of the Bonna Realty Group, adding that he is personally in favour of restoration where possible.

“We need some funds to support or projects to buy those properties and renovate them and use them for tourism purpose.”

Heritage Mission’s Ulisse agrees, saying, “If we don’t do something now, we will lose a lot of these heritage buildings.”

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© 2014 dpa Deutsche Presse-Agentur GmbH. All rights reserved.

Zaha Hadid Designs Five Wooden Towers To House Cambodian Genocide Institute


This post originally appeared on ArchDaily.
by Karissa Rosenfield


Zaha Hadid Architects have unveiled their design for the Sleuk Rith Institute in Phnom Penh. The highly-anticipated project, commissioned by the Documentation Center of Cambodia’s (DC-Cam), will serve as Cambodia’s go-to archive for Khmer Rouge history and a leading center for genocide studies in Asia.,hadid,designs,five,wooden,towers,to,house,cambodian,genocide,institute,arts

Five wooden towers, inspired by ancient Angkorian architecture, will house the institute’s “cross-section of pursuits,” including a genocide research center, graduate school, museum, document archives and research library. As the towers rise, the structures will interweave and link, connecting various departments above the ground level and uniting the institution as a singular whole.


From the architects: A vision of Youk Chhang, a tireless human rights activist and investigator of the Khmer Rouge atrocities, the Sleuk Rith Institute will house the Documentation Centre of Cambodia’s one million document archive and, as the largest collection of genocide related material in Southeast Asia, will become a global centre for education and research into the documentation, causes and prevention of genocide.

Despite the tragic history explored at the institute, Youk Chhang’s research led to the very considered brief for a building that promoted reflection and reconciliation, and also inspired and innovated. “We were keen to create a forward-looking institution that deviates from the distress-invoking, quasi-industrial, harshness of most existing genocide memorial models. This is not to criticize or denigrate such models but, instead, to emphasize that in light of a Cambodia’s rich cultural and religious traditions, we must move in a different and more positively-oriented direction,” stated Chhang.

“The best memorials are not objects we visit once, contemplate, and file away. The best memorials evoke reflection and commemoration, but are also living, dynamic public places that engage with all generations in the community,” continues Chhang.


The institute’s design is organized as five wooden structures that are separate volumes at ground level, but interweave and link together as they rise upwards; connecting the different departments, visitors, students and staff within a singular whole. With an overall footprint of 80 meter x 30 meter at the base and 88 meter x 38 meter at roof level, the structures range between three to eight stories.

Each of these five buildings will house a different function: the Sleuk Rith Institute; a library holding the largest collection of genocide-related material in Southeast Asia; a graduate school focussing on genocide, conflicts and human rights studies; a research centre and archive to influence national and regional policies and discourse; a media centre and an auditorium that can be used by the institute and the entire community.


The architecture of the ancient temple site Angkor Wat, and Cambodia’s many other remarkable Angkorian sites, builds complexity by combining and interlocking a multitude of geometric forms in a formal progression of connected enclosures. As they gain in height and coalesce, the Sleuk Rith Institute’s five buildings define an intricate spatial composition of connecting volumes; generating a series of exterior and interior spaces that flow into each other to guide visitors through the different areas for contemplation, education, engagement and discussion.

The design connects the museum, library, school and institute at various levels, allowing different users to interact and collaborate, enhancing their understanding and experience. Yet each of the institute’s functions is also able to operate independently when required.


Constructed from sustainably-sourced timber, the primary structure, exterior shading and interior partitions give natural scale, warmth and materiality. The more complex forms have been designed and engineered to be assembled from economical straight and single-curved timber sections with established technologies.

The site is located in the grounds of the Boeung Trabek High School in Phnom Penh, south of the city centre. The existing school buildings (now abandoned when the high school moved to its new premises) were used as a re-education camp during the Khmer Rouge regime – as were many schools in Cambodia – making this a fitting location for the Institute: building on the past to educate the future.

To accommodate Cambodia’s tropical climate, the narrower lower levels of the institute are shaded by the building’s form, while louvers on the upper levels keep out strong sunshine. Located at the confluence of the Mekong and Tonlé Sap Rivers, the institute’s buildings will be built on raised terraces, to protect from Phnom Penh’s seasonal flooding.


Visitors approach the building on causeways above reflecting catchment pools that mirror the building’s form and bring light deep into the internal spaces. As with the catchment pools of Cambodia’s ancient temple sites including Sras Srang and Angkor Wat, these pools – and those on the upper level courtyard and terraces – will be fed by harvested rainwater and are integral to the institute’s water management processes that minimize the impact on the local environment and drainage systems.

Entering through the atrium at the centre of the building, visitors are welcomed by exhibits from the Institute’s collection. From here visitors are directed to the museum where exhibitions continue or to the school and auditorium. The auditorium is on ground level while classrooms and professors’ offices are organized around the outdoor courtyard above and continue on upper floors.

Above the entry atrium, the Institute houses the Documentation Centre archive, with offices for researchers and Institute administration on the top levels. A bridge is suspended above the atrium to connect the school and library.


The building’s passive design – including measures to reduce energy and water consumption while increasing system efficiencies, and the installation of renewable energy sources – will increase its ecological performance. The institute’s form minimizes solar gain, and the external shading system will be varied on each elevation to reduce solar gain whilst maintaining sufficient daylight levels where required. Thermal buffer zones protect the archive and exhibition spaces and further reduce energy consumption. Water condensation from the air handling will be recovered for reuse and foul water will be treated on-site via bio-reactors or a natural plant-based wastewater treatment system that can be incorporated within the park.

The horizontal roof of the building is hidden from view to house renewable energy sources that are extremely effective in Phnom Penh’s climate: photovoltaic cells for power and a solar thermal array for hot water generation. Plant and air-system heat exchangers will also be located on the roof, maximizing the area within the building for the institute’s commemorative, educational, cultural and community programs.


The institute includes a 68,000 square meter memorial park for the entire community with sport fields, urban vegetable garden and fruit orchards, traditional meadows and a forest that will house contemporary Cambodian sculptures, many of these commemorating the women that helped to rebuild the country. The park slopes away from the building to provide further protection against seasonal flooding. The southern end of the park is landscaped to become a large retention pond during heavy monsoon rains, alleviating the city’s existing flood drainage. The park’s many pedestrian paths link together neighboring streets that had previously been disconnected, inviting the local community into the heart of the institute.

The Sleuk Rith Institute complex has been granted approval and is scheduled to start construction on site next year.

Architects: Zaha Hadid Architects
Location: Phnom Penh, Cambodia
Design: Zaha Hadid, Patrik Schumacher
Zha Design Director: DaeWha Kang
Zha Lead Designer/ Project Leader: Brian Dale
Zha Project Team: Malgorzata Kowalczyk, Michal Wojtkiewicz, Torsten Broeder, Fernanda Mugnaini
Client: Sleuk Rith Institute
Client Director: Youk Chhang
Structure / Mep / Façade / Lighting / Acoustics: Arup
Project Manager / Structure Lead: Ben Lewis
Mep Lead: Emmanuelle Danisi
Facade Lead: Jonathan Wilson
Lighting: Giulio Antonutto
Acoustics: Philip Wright
Consultant Project Team: Chris Carroll (Project Director); Vincenzo Reale, Jason Simpson, Edward Clarke Anne Gilpin, Toby Clark, Sara Clark, Michael Young
Landscape Architects: AECOM – Phil Black (Design Director), Mun Pheng Mak (Project Manager), Sarmistha Mandal (Associate); Hwei Hwei Chan, Akarapol Chongwattanaroj, Eunice Chia, Chung Ho Kim (Design Team)
Renders: MIR
Illustrations: Jan-Erik Sletten
Film: Viktor Fretyán
Photographs: Courtesy of ZHA

Cite: Rosenfield, Karissa. “Zaha Hadid Designs Five Wooden Towers to House Cambodian Genocide Institute” 10 Oct 2014. ArchDaily. Accessed 17 Oct 2014.

Once Upon A Time….Phnom Penh City

From KA Tours:

The Institut français (French Institute) in partnership with the Heritage Mission of Cambodia has organized the following event:

Once Upon a time… Phnom Penh city
on Tuesday, September 30th at 6.30pm
at the Institut français – 218, street 184, Phnom Penh

This two-week long event is dedicated to the urban ‘story’; the past, present and future development of Phnom Penh.  It includes 2 exhibitions, an architecture contest on the theme “New Look Shophouses”, a screening series and 3 conferences (more info here).
Tuesday 30 Sept Opening Evening ‘Once Upon a Time…Phnom Penh City’
Thursday 2 Oct  Presentation: Phnom Penh Heritage City
Tuesday 7 Oct  Presentation: Sangkum: An Urban History
Tuesday 14 Oct  Presentation: Phnom Penh Today and After
All lectures/ presentations begin at 6:30 pm.
For those who took interest in our colonial and 1960s tours, this event is not to be missed!

Flooding Risk From Climate Change, Country by Country

Continue reading the main story

If global carbon emissions
continue on current trends
are reduced sharply
are reduced extremely sharply
and sea levels are affected by climate change
much more than expected
about as much as expected
much less than expected
about 2.6 percent of the global population (about 177 million people) will be living in a place at risk of regular flooding.
AngolaArgentinaAustraliaAustraliaBel.BangladeshBrazilCanadaChileChinaIv. CoastCam.CongoColombiaCubaGer.Dom. Rep.Alg.EcuadorEgyptSpainFra.GBRGhanaGui.GreeceGuatemalaIndonesiaIndiaIranIraqIta.JapanKenyaCam.Kor.SriLankaMoroccoMadagascarMexicoMyanmarMoz.MalaysiaNig.NetherlandsPak.PeruPhilippinesPol.N.KorPor.Rom.RussiaSaudiArabiaSudanSen.SyriaThailandTunisiaTurkeyTaiwanTanzaniaUkr.UnitedStatesVenezuelaVietnamYem.South Africa

Share of population exposed to coastal flooding
Boxes represent coastal countries and are sized according to the number of people expected to be exposed to regular flooding by 2100.
People exposed by continent

146.5 mil.
16.9 mil.
4.8 mil.
4.5 mil.
3.3 mil.
0.7 mil.
Continue reading the main storyShare This Page

More than a quarter of Vietnam’s residents live in areas likely to be subject to regular floods by the end of the century. Four percent of China’s residents — 50 million people — live in the same kind of areas. Across the globe, about one person in 40 lives in a place likely to be exposed to such flooding by the end of the century, absent significant changes.

These figures are the result of a new analysis of sea levels and flood risk around the world, conducted by Climate Central and based on more detailed sea-level data than has previously been available. The analysis offers country-by-country estimates for populations at risk of regular flooding, accounting for a range of potential emissions reductions and for variations of sea level sensitivity to climate change.

Globally, eight of the 10 large countries most at risk are in Asia. The Netherlands would be the most exposed, with more than 40 percent of its country at risk, but it also has the world’s most advanced levee system, which means in practice its risk is much lower.

Some countries in Asia may choose to emulate the Dutch system in coming decades, but some of the Asian nations are not wealthy and would struggle to do so.

The analysis offers more evidence that the countries emitting the most carbon aren’t necessarily the ones that will bear the brunt of climate change. The United States — one of the world’s largest carbon emitters per capita and historically the overall largest emitter — ranks 34th on the list of risk of flood exposure, between India and Madagascar. The share of Americans projected to be exposed to regular flooding — about 1 percent — might seem small, but it’s still about 3.1 million people, more than live in Chicago and Minneapolis combined.

China, on the other hand, leads the world in both current emissions and greatest number of people exposed to flood risk.

Climate Central, a news organization and research group, has released the new analysis as the United Nations gathers this week for a summit on climate change. Climate scientists expect flooding to increase as global warming melts snow and ice and expands the volume of oceans. The analysis defines regular flooding as a flood at least once every three years.

Of course, there is substantial uncertainty about the future of carbon emissions, global warming and sea levels. The map above includes estimates, given current trends, for the most likely possibility but also the extreme low and high estimates for sea levels and flood risk. Climate change could occur at a different pace than expected, and governments will surely vary in the aggressiveness of their policy responses.

The analysis, conducted by Benjamin Strauss and Scott Kulp, finds:

■ About 2.6 percent of the world’s population — about 177 million people — live in areas that will be vulnerable to chronic flooding within the next 100 years. At minimum, even with extremely rigorous cuts to global emissions and with oceans much less sensitive to climate change than expected, 1.9 percent of the population of coastal countries would be affected. At worst, the figure would be 3.1 percent.

■ Flood-exposure estimates, including those shown above, may still understate the risks. Using more detailed elevation data for the United States than is available globally, for instance, the group found that estimated flood exposure was probably much too conservative. Applied globally, that means more than 500 million people could be living in places that are at risk of regular flooding in the next century.

Climate Central has published a detailed description of its methodology and data on its website.

Beyond Angkor: How lasers revealed a lost city

Angkor Wat temple

Deep in the Cambodian jungle lie the remains of a vast medieval city, which was hidden for centuries. New archaeological techniques are now revealing its secrets – including an elaborate network of temples and boulevards, and sophisticated engineering.

In April 1858 a young French explorer, Henri Mouhot, sailed from London to south-east Asia. For the next three years he travelled widely, discovering exotic jungle insects that still bear his name.

Today he would be all but forgotten were it not for his journal, published in 1863, two years after he died of fever in Laos, aged just 35.

Mouhot’s account captured the public imagination, but not because of the beetles and spiders he found.

Readers were gripped by his vivid descriptions of vast temples consumed by the jungle: Mouhot introduced the world to the lost medieval city of Angkor in Cambodia and its romantic, awe-inspiring splendour.

“One of these temples, a rival to that of Solomon, and erected by some ancient Michelangelo, might take an honourable place beside our most beautiful buildings. It is grander than anything left to us by Greece or Rome,” he wrote.

His descriptions firmly established in popular culture the beguiling fantasy of swashbuckling explorers finding forgotten temples.

Today Cambodia is famous for these buildings. The largest, Angkor Wat, constructed around 1150, remains the biggest religious complex on Earth, covering an area four times larger than Vatican City.

It attracts two million tourists a year and takes pride of place on Cambodia’s flag.

Find out more

Dr Dan Penny finds medieval carvings under a stone bridge in the Cambodian jungle

Follow the archaeological team in Cambodia as they uncover the mysteries of Angkor Wat. Watch Jungle Atlantis on Thursday 25 September at 20:00 BST on BBC Two or catch it later on the BBC iPlayer.

But back in the 1860s Angkor Wat was virtually unheard of beyond local monks and villagers. The notion that this great temple was once surrounded by a city of nearly a million people was entirely unknown.

It took over a century of gruelling archaeological fieldwork to fill in the map. The lost city of Angkor slowly began to reappear, street by street. But even then significant blanks remained.

Then, last year, archaeologists announced a series of new discoveries – about Angkor, and an even older city hidden deep in the jungle beyond.

An international team, led by the University of Sydney’s Dr Damian Evans, had mapped 370 sq km around Angkor in unprecedented detail – no mean feat given the density of the jungle and the prevalence of landmines from Cambodia’s civil war. Yet the entire survey took less than two weeks.

Their secret?

Lidar – a sophisticated remote sensing technology that is revolutionising archaeology, especially in the tropics.

Mounted on a helicopter criss-crossing the countryside, the team’s lidar device fired a million laser beams every four seconds through the jungle canopy, recording minute variations in ground surface topography.

The findings were staggering.

Image showing what is beneath the ground at AngkorLidar technology has revealed the original city of Angkor – red lines indicate modern features including roads and canals

The archaeologists found undocumented cityscapes etched on to the forest floor, with temples, highways and elaborate waterways spreading across the landscape.

“You have this kind of sudden eureka moment where you bring the data up on screen the first time and there it is – this ancient city very clearly in front of you,” says Dr Evans.

These new discoveries have profoundly transformed our understanding of Angkor, the greatest medieval city on Earth.

Phra Sav Ling Povn, palace of the leprous king, near the great temple of Angkor Wat, circa 1930Phra Sav Ling Povn, palace of the leprous king, near Angkor Wat, circa 1930

At its peak, in the late 12th Century, Angkor was a bustling metropolis covering 1,000 sq km. (It would be another 700 years before London reached a similar size.)

Angkor was once the capital of the mighty Khmer empire which, ruled by warrior kings, dominated the region for centuries – covering all of present-day Cambodia and much of Vietnam, Laos, Thailand and Myanmar. But its origins and birthplace have long been shrouded in mystery.

A few meagre inscriptions suggested the empire was founded in the early 9th Century by a great king, Jayavarman II, and that his original capital, Mahendraparvata, was somewhere in the Kulen hills, a forested plateau north-east of the site on which Angkor would later be built.

But no-one knew for sure – until the lidar team arrived.

The lidar survey of the hills revealed ghostly outlines on the forest floor of unknown temples and an elaborate and utterly unexpected grid of ceremonial boulevards, dykes and man-made ponds – a lost city, found.

Relief map of Mahendraparvata

Most striking of all was evidence of large-scale hydraulic engineering, the defining signature of the Khmer empire.

By the time the royal capital moved south to Angkor around the end of the 9th Century, Khmer engineers were storing and distributing vast quantities of precious seasonal monsoon water using a complex network of huge canals and reservoirs.

Harnessing the monsoon provided food security – and made the ruling elite fantastically rich. For the next three centuries they channelled their wealth into the greatest concentration of temples on Earth.

One temple, Preah Khan, constructed in 1191, contained 60t of gold. Its value today would be about £2bn ($3.3bn).

But despite the city’s immense wealth, trouble was brewing.

At the same time that Angkor’s temple-building programme peaked, its vital hydraulic network was falling into disrepair – at the worst possible moment.

The end of the medieval period saw dramatic shifts in climate across south-east Asia.

Tree ring samples record sudden fluctuations between extreme dry and wet conditions – and the lidar map reveals catastrophic flood damage to the city’s vital water network.

With this lifeline in tatters, Angkor entered a spiral of decline from which it never recovered.

In the 15th Century, the Khmer kings abandoned their city and moved to the coast. They built a new city, Phnom Penh, the present-day capital of Cambodia.

Life in Angkor slowly ebbed away.

Angkor Wat

When Mouhot arrived he found only the great stone temples, many of them in a perilous state of disrepair.

Nearly everything else – from common houses to royal palaces, all of which were constructed of wood – had rotted away.

The vast metropolis that once surrounded the temples had been all but devoured by the jungle.

Watch the first episode of Jungle Atlantis on Thursday 25 September at 20:00 BST on BBC Two, or catch it later on the BBC iPlayer. The programme was made in association with The Smithsonian Channel, which will be transmitting both episodes in the US on 5 October under the title Angkor Revealed.

How Sand Became One of Phnom Penh’s Hottest Commodities


How Sand Became One of Phnom Penh’s Hottest Commodities

Sand from the Tonle Sap River is worth millions of dollars, and even more overseas. (Photo by Prince Royvia Flickr)

The 200 families with homes next to the Tonle Sap River in Phnom Penh’s Deum Kor village live in front of what looks like a man-made beach. On one side of the main road cutting through Deum Kor, there is the riverside part of the community, with houses, shops and boats. On the other side of the road, there is nothing but a vast expanse of sand.

Phnom Penh’s construction frenzy is fueling the need for sand dredging, the practice of sucking up debris from riverbeds. The sand is normally used to clear waterways and to provide material for development projects. According to the Cambodian government, between 15,000 to 20,000 cubic meters of sand per day is needed in Phnom Penh to sustain the city’s building boom. Sand dredging, which in Khmer translates to “getting the sand out of the water,” is a common practice around the world. But for many here, it’s a symbol of what ails the city: shoddy urban planning and a Wild West approach to development.

Once dredged, the sand has to go somewhere. Deum Kor, like other riverside communities, is one of the places it gets dumped. After getting the sand out of the water, workers pile it onto floating barges, then haul it to the banks. Aided by water, the sand then sluices through tubes that extend up onto the land. It eventually winds up on construction sites. The sand becomes the groundwork for apartment buildings and developments that will forever change the landscape of Deum Kor, where residents can still point to the oldest house in the village, as if highlighting its unique connection to an irretrievable past.

“Before, we planted rice to eat by ourselves,” says Hun Yub, a 65-year-old woman with several relatives in the village. “But now, our villagers work as construction workers to get money to buy rice and vegetables.” Sitting on the steps of her wooden house, built on stilts to avoid flooding, she laughs at the irony.

A former soldier who declines to give his name says the dredging operations started up a few years ago. His two sons work as security guards for a construction firm that uses the sand. Now they support him financially – before, he had rented rice fields to farm on, but his landlord sold them to one of the companies. Though he doesn’t actively resist the dredging, he describes an uneasy coexistence with his new neighbors.

“We as villagers tolerate them to operate with the sand in the daytime only. At night it is noisy and we could not sleep,” he says, referring to the racket produced by the industrial machinery. “They seem afraid of us and dare not to dredge at night, or I will hack and destroy their tubes.”

In Cambodia, sand dredging has been controversial for years. In 2009, Prime Minister Hun Sen announced a ban on sand exports, which were being used for land reclamation projects abroad, mainly in Singapore. According to a 2008 report from the London-basedNGO Global Witness, the sand, extracted for the most part from the winding Tatai River in the southwestern province of Koh Kong, was worth at least $8.6 million annually at the point of extraction – and some $35 million in retail value once in Singapore.

The 2009 ban cited environmental concerns – dredging has been blamed for riverbanks collapsing and for disturbing marine life – but a growing eco-tourism industry in the area probably also factored into the decision. With the ban, however, came significant loopholes. Dredging would be allowed where sand replenished itself naturally in the riverbed, to help unblock waterways, and, crucially, to meet domestic consumption.

Domestic consumption meant construction, and that meant dredging in Phnom Penh would continue unabated. The demand for sand was too high. Even in 2013, when the government, concerned about the combination of massive flooding and dredging, put a stop to the practice within the city limits, it continued to allow dredging in specific areas.

Chan Yutha, a spokesman for the Ministry of Water Resources and Meteorology, says that a new committee has been established to monitor and examine the dredging sites. The 2013 ban, says Yutha, “blocked local construction, so the government made a decision to allow about five companies to operate sand dredging at two locations in Phnom Penh.” He adds that the operations also help the flow of the river and have a beneficial, not detrimental, impact on the lives of its fish.

“Before, the demand for sand was less. The more construction buildings, the more sand is needed. Nowadays, most of the sand is used to fill the land in building construction,” he says.

But critics of the practice say that rampant, unregulated dredging, and the filling in of land that results from it, is changing the lives of communities for the worse.

“Dredging causes changes in water levels, which causes landslides and unstable river banks. The housing of these communities collapses, and they can lose the land they use to grow their food,” says Ee Sarom, acting executive director of housing rights NGOSahmakum Teang Tnaut. Sarom points to Phnom Penh’s Boeung Kak Lake, which was filled in with sand to make way for a development that has come to naught, as well as other sites around the city, as living evidence of the problem.

“Sand is not only ruining the ‘look’ of Phnom Penh, it is a symbol of everything that is environmentally and socially reckless about the approach to urban development in Phnom Penh,” he adds. “It is symbolic of the prioritization of economic growth over ensuring that the most vulnerable communities and general residents of Phnom Penh have access to a green city, with affordable housing, functioning infrastructure and a healthy environment.”

Those conflicts are on full display in Deum Kor, where one 26-year-old dredging worker, who identifies himself as Run, says that although he makes an enviable salary of $600 a month, dredging is “not good” because it harms the riverbank and causes collapses. The village chief contends otherwise, and also says that 87 families are going to get new plots of land farther back on the man-made beach.

Many are split between the economic benefits and the realization that they are working to change their own community, leaving them in an uncertain future.

Yub, the former rice farmer, ponders the two sides of the argument. A dredging company had paid her $100 a month to park in front of her house. But that doesn’t wholly justify it in her mind. Things aren’t worse, but they aren’t great either. In a way, she’s beholden to dredging. ”It is difficult for us to say that our standard of living is getting better now.”



Hun Sen’s Cambodia


    • Available Nov 25, 2014
      344 p., 6 x 9
      33 b/w illus.
      ISBN: 9780300190724
      Cloth: $37.50

Hun Sen’s Cambodia


  • Sebastian Strangio
      REVIEWS             PREVIEW             CONTENTS             EXCERPTS      

To many in the West, the name Cambodia still conjures up indelible images of destruction and death, the legacy of the brutal Khmer Rouge regime and the terror it inflicted in its attempt to create a communist utopia in the 1970s. Sebastian Strangio, a journalist based in the capital city of Phnom Penh, now offers an eye-opening appraisal of modern-day Cambodia in the years following its emergence from bitter conflict and bloody upheaval.

In the early 1990s, Cambodia became the focus of the UN’s first great post–Cold War nation-building project, with billions in international aid rolling in to support the fledgling democracy. But since the UN-supervised elections in 1993, the nation has slipped steadily backward into neo-authoritarian rule under Prime Minister Hun Sen. Behind a mirage of democracy, ordinary people have few rights and corruption infuses virtually every facet of everyday life. In this lively and compelling study, the first of its kind, Strangio explores the present state of Cambodian society under Hun Sen’s leadership, painting a vivid portrait of a nation struggling to reconcile the promise of peace and democracy with a violent and tumultuous past.

Sebastian Strangio is a former reporter and editor at the Phnom Penh Post, Cambodia’s oldest English-language newspaper. He is currently a freelance correspondent covering news and events across the Asia-Pacific. Strangio lives in Phnom Pen

A comprehensive archaeological map of the world’s largest preindustrial settlement complex at Angkor, Cambodia


A comprehensive archaeological map of the world’s largest preindustrial settlement complex at Angkor, Cambodia

  1. Damian Evans * , ,
  2. Christophe Pottier ,
  3. Roland Fletcher § ,
  4. Scott Hensley ,
  5. Ian Tapley ,
  6. Anthony Milne**, and
  7. Michael Barbetti ††
  1. Edited by Michael D. Coe, Yale University, New Haven, CT, and approved June 29, 2007 (received for review March 17, 2007)


The great medieval settlement of Angkor in Cambodia [9th–16th centuries Common Era (CE)] has for many years been understood as a “hydraulic city,” an urban complex defined, sustained, and ultimately overwhelmed by a complex water management network. Since the 1980s that view has been disputed, but the debate has remained unresolved because of insufficient data on the landscape beyond the great temples: the broader context of the monumental remains was only partially understood and had not been adequately mapped. Since the 1990s, French, Australian, and Cambodian teams have sought to address this empirical deficit through archaeological mapping projects by using traditional methods such as ground survey in conjunction with advanced radar remote-sensing applications in partnership with the National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL). Here we present a major outcome of that research: a comprehensive archaeological map of greater Angkor, covering nearly 3,000 km2, prepared by the Greater Angkor Project (GAP). The map reveals a vast, low-density settlement landscape integrated by an elaborate water management network covering >1,000 km2, the most extensive urban complex of the preindustrial world. It is now clear that anthropogenic changes to the landscape were both extensive and substantial enough to have created grave challenges to the long-term viability of the settlement.

The first century of scholarship on Angkor, in Cambodia, was dominated by the need to conserve and restore the monuments, to locate Khmer civilization within broader cultural history, and to establish a basic chronological framework for Angkor and its Southeast Asian empire [9th–16th centuries Common Era (CE)]. In the early 1950s, Bernard-Philippe Groslier of the École Française d’Extrême-Orient (EFEO) became the first scholar to pay serious attention to the traces of a hydraulic network that had been partially mapped in the first half of the 20th century. Groslier surmised that it was both built and used for irrigation, specifically, to ameliorate variations in agricultural output caused by an unpredictable annual monsoon and to support a huge population of greater than a million people (1) in a constellation of suburbs. He also argued that the extent and breakdown of the network was implicated in the demise of Angkor (1, 2).

As one of the very few scholars in the 20th century with both an awareness of and an interest in the settlement pattern surrounding the monuments, Groslier also understood that a comprehensive and integrated program of archaeological research, including ground survey, remote sensing, and archaeological mapping, was needed to broaden the perspective beyond the great monuments and to provide a firm basis for assessing his theory (15). Importantly, he commissioned topographic maps of Angkor at 1:10,000 scale (5) that provided a much-needed foundation for archaeological mapping.

However, the burden of the conservation d’Angkor in the 1960s and the dire circumstances of Cambodia from the 1970s to the early 1990s made it impossible to fully realize his agenda: his archaeological mapping never went beyond the preliminary and raw topographic base maps, which remained unpublished until 1993 (6). Additionally, these maps were never completed for the area north of Angkor Thom, thus reinforcing a longstanding focus on the central and southern areas at the expense of the northern region. As a result, Groslier continued to use simple schematic maps to develop his theory (1) and Angkor remained, until the early 1990s and still to some extent even today, only partially understood as a settlement, as an inhabited space in which much of the economic, residential, agricultural, and probably even ritual activity took place beyond the walled enclosures and great stone temples of central Angkor.

Since the early 1990s, successive cartographic projects have sought to address this empirical deficit by producing detailed archaeological maps of the Angkor region. These maps include the main temples but also detail the residential areas, fields, and infrastructure that stretched far beyond the massive sandstone constructions (710). In the 1990s, the temple-centric focus of Angkorian studies was, for the first time, comprehensively challenged by the development of a new map of the central and southern areas of Angkor by Christophe Pottier of the EFEO (9, 10). His work originally grew out of the need to map and document the landscape of Angkor for the purposes of the United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage nomination and site management. Noticing the puzzling dichotomy between the clusters of monuments on the earlier maps and the hundreds of newly identified local temples dispersed across the landscape, Pottier then developed the mapping on a more precise scale by collating existing maps and documentation, analyzing aerial photographs and undertaking systematic field surveys. His final map, completed in 1999 (10), thus documented a built landscape of occupation mounds, local temples, and household ponds interspersed among the great monuments and the hydraulic works associated with them (Fig. 1).

Fig. 1.

Oblique aerial views of remnant Angkorian urban features. (Upper Left) Occupation mounds and ponds. (Upper Right) Canals and embankments. (Lower Left) Multifunction roadway/canals. (Lower Right) Classic “village temple” configuration.


Pottier also showed decisively that the great reservoirs, or barays, had inlets and outlets and were connected to a network of channels and embankments, contrary to the assertions of critics of Groslier’s hydraulic thesis from the 1980s onwards (1114). Moreover, the longstanding assumption (2, 11) that the extensive agricultural field systems visible on the surface today might date from Angkorian times was supported by his new map, which displayed the integral connection between the local temples and their agricultural space (15). Various other elements of the classical Angkorian landscape, in particular, the small ponds described in an account of Angkor in the 13th century (16), have also persisted on the surface, were clearly identifiable from the air and have often been renovated and reused by the contemporary Khmer population. Archaeological evidence of Angkorian occupation (in particular, brick and ceramic debris) was consistently found at the sites that had been identified from the air and was documented and collected wherever appropriate (10). Field verification continues across the greater Angkor region in a process that has consistently matched aerial observations with surface evidence. Recent excavations at the Siem Reap airport (17) and elsewhere have provided further stratigraphic evidence of continuity between subtle topographic features visible on the surface today and the urban landscape of medieval Angkor.

Pottier’s new study used the maps commissioned by Groslier as a cartographic base (because they were the only available ones at that time), and began the process of creating a comprehensive archaeological map of Angkor by recording several thousand of these features and part of agricultural field system within an area of ≈1,000 km2. The coverage of that survey was limited to the southern and central parts of Angkor by the available cartographic base and by the persistent security risks in Siem Reap Province until 1998. However, it was clear from remote sensing that the contiguous settlement space of Angkor extended well beyond what had been mapped; further survey was therefore required.

Since the completion of Pottier’s initial mapping in 1999, the Greater Angkor Project (GAP), an international research program (Australian, Cambodian, and French) focusing on the spatial structure, the water management network, and the reasons for the decline of Angkor, has continued to extend the spatial coverage of detailed archaeological mapping by using a diverse range of data sources, field techniques, and, notably, airborne imaging radar (AIRSAR) data acquired for GAP in 2000 by National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL).


One of the first tasks was the digitization of Pottier’s 1999 hand-drawn map and the conversion of its data into a geographic information system. Subsequent mapping work has concentrated on the use of airborne radar imaging (AIRSAR/TOPSAR) for archaeological survey, in particular using data acquired over Angkor in September 2000 by NASA/JPL on behalf of GAP (18), expanding on previous radar data acquisitions in 1994 on behalf of the World Monuments Fund (SIR-C/X-SAR) and in 1996 on behalf of Elizabeth Moore of the University of London, London, U.K. (AIRSAR). The first stage of GAP’s analysis, begun in 2001 and completed in 2002, was undertaken with a view to very quickly producing a “broad-brush” picture of the settlement pattern to the north of Pottier’s study area. The specific aims were to gain an understanding of the interaction of microwave sensors with the archaeological landscape, to develop and refine methods of systematically applying imaging radar to an archaeological investigation, and to assess the feasibility and likely outcome of a more detailed survey incorporating heterogeneous data sources.

The AIRSAR instrument is an active sensor with the ability to penetrate clouds. On its 2000 deployment over Angkor, multiple channels of data (C band at 3 cm, L band at 25 cm, and P band at 64 cm, with polarisation measured at transmit and receive) were aquired over ≈8,000 km2 through 98% cloud cover. The ability of the AIRSAR instrument to produce high-quality, high-resolution data sets describing surface roughness and electrical properties is well documented [Jet Propulsion Laboratory (2006) AIRSAR Airborne Synthetic Aperture Radar Documentation. Available at] and does not warrant detailed treatment here. It is, however, worth noting that the ability of the instrument to distinguish very subtle differences in surface vegetation and surface moisture was of particular use in uncovering the archaeological landscape at Angkor. The distinctive spatial patterning of features manifests itself primarily in slight variations in topographic relief, which in turn produces variations in the species of surface vegetation and soil humidity. These strongly influence the amplitude or “brightness” of the radar signal returned to the sensor.

A very important example of this phenomenon is the local temple, which usually consists of a ≈20-m square central mound of ≈0.5 m to 2 m in height, surrounded by a shallow moat of less than ≈1 m in depth and usually traversed by an earthen causeway on its eastern side, lending the moat-and-mound complex a distinctive spatial structure. This complex in turn typically has a small rectangular reservoir immediately to the east, whose orientation is generally east-to-west and whose ratio of length to width is ≈2:1. Some of the local temples have architectural remains such as bricks scattered on the surface and are well known as temple sites, whereas many others have been completely subsumed by modern residential or agricultural developments and are essentially undetectable on the ground. Most of these temples, however, can be detected in the radar imagery. For example, in many cases the slightly lower elevations of the rice fields in the former moat and reservoir and the slightly higher elevations of the fields built on top of the remnant mound and reservoir banks result in different stages of rice maturity and in differential levels of soil moisture content, which strongly affect the returned radar signal. Moreover, the bunds of the rice fields act as very bright corner reflectors to the radar signal. The fact that remnant moats and reservoirs are usually subdivided into these fields serves to delineate the typical spatial configuration of a temple site very clearly within the radar imagery. For the same reasons, the identification and mapping of Angkorian field systems, linear features such as roads and canals, and the ponds that surround the local temples can be performed very quickly and effectively using these data (19).

From 2000 to 2002, some 1,500 km2 of the landscape beyond Pottier’s 1999 map were studied from the AIRSAR images (7), with all features documented and mapped within a geographic information system environment. The results of this initial survey were extremely promising. A highly complex linear network to the north of Angkor was revealed, adding great detail to the area described by Groslier, as well as significant residential and agricultural development throughout a large part of the study area. The GAP excavations have indicated a degree of human occupation along some of the embankments and channels of the network (8), connecting the infrastructure to the residential pattern of Angkor. The mapping also showed that Angkor had a complex, tripartite, water management network for systematically stabilizing, storing, and dispersing water.

The preliminary archaeological map of the Angkor area resulting from the AIRSAR study has, until now, represented the most complete picture of the settlement. Importantly, although the map and any conclusions drawn from it were highly provisional, it became increasingly clear from this work that the site represented possibly the largest complex of low-density urban development in the preindustrial world.

Ultimately, however, the ability of this map to provide a final, decisive picture of the settlement landscape of Angkor was limited by the horizontal spatial resolution of the radar data. At 5 m it did not allow the consistent recognition of occupation mounds and made the identification of local temples and small ponds problematic. Also, the methodology was dedicated as much toward assessing the radar’s capabilities as it was toward the particular historical problem of urban development at Angkor.

The next stage of mapping, from 2003 to 2007, was designed to move the cartographic project toward a definitive conclusion. A notable change from previous surveys of Angkor was the specification of a nonarbitrary survey boundary. In light of the GAP focus on the extent of human manipulation of water resources, it was decided to use the watershed catchment boundaries of Angkor’s rivers ‡‡ to define a study area. The study area covers 2,848 km2, divided into 1-km grid squares. Each was analyzed individually in detail, with consideration given to all of the available evidence, including the diverse site inventories, every archaeological map produced over the last century, topographic data sets, and remotely sensed data from a range of sources, including Landsat, ASTER, SPOT, AIRSAR, Ikonos, Quickbird, and conventional aerial photography, in particular the 1:25,000-scale Finnmap 1992 coverage already used by Pottier (10).

The understanding of radar’s interaction with the archaeological landscape developed in the previous study was brought to bear heavily on this work, which was considerably enhanced by the delivery in 2003 by NASA/JPL of a digital elevation model derived from the September 2000 AIRSAR deployment. This TOPSAR data set specifies a height value for every 5 m2 of the landscape with submeter accuracy and allows for extremely precise analyses of the subtle topographic variations that characterize remnant Angkorian features.

In contrast to the radar-derived preliminary archaeological map of 2002, the 2007 map is conservative in the features mapped and displayed. A feature had to be visible in at least two different data sources or to be verified from ground level or low-altitude aerial-survey to satisfy the criteria for inclusion. It is anticipated, therefore, that a number of features will be added to the map as verification continues, just as some features will inevitably prove to be post-Angkorian and will need to be removed. This process continues even for Pottier’s map, which has been well verified and covers areas that have been intensively studied for over a century. It is extremely unlikely, however, that the addition or subtraction of a relatively small number of minor features will qualitatively alter the current representation of settlement space and the overall layout of the water management network. In this sense the map presented here can be considered definitive.


The final phase of the mapping work, completed in 2007 and presented here (Fig. 2), reveals Angkor as an extensive settlement landscape inextricably linked to the water resources that it increasingly exploited over the first half of its existence. It was not simply a succession of spatially distinct ceremonial centers or a carefully planned sacred space but, as Coe suggested in 1957 (20), a low-density urban complex like the Classic Maya cities of the Yucatan peninsula such as Tikal (21). As with modern low-density cities and the Classic Maya cities, Angkor was a cumulative settlement palimpsest, with an organic and polynuclear form arising from social and environmental processes operating over more than half a millennium.

Fig. 2.

A new archaeological map of Greater Angkor.


Angkor is visibly an infrastructural network, along which people also lived, imposed on the regional pattern of the residential landscape north of the Tonle Sap. The large-scale infrastructure gave coherence to the scatter of traditional residential units and “created” Greater Angkor as a corporate entity. The key question is the extent of the low-density urban complex. The critical point is that the smaller component of the settlement pattern (the local temples, the occupation mounds, the ponds, and the durable and highly structured web of agricultural space that binds them) occurs with remarkable consistency within ≈15–25 km of the current high-water mark of the lake. Furthermore, an analysis of the Landsat data shows that this form of small-scale, low-density occupation continues essentially uninterrupted far beyond the north-western and south-eastern boundaries of the study area, and there is evidence of contiguous, even lower-density occupation across a large swathe of the Cambodian landscape (see Fig. 3). Although there are areas of somewhat more concentrated occupation, there is, at this stage, no particular spatial or temporal pattern that lends itself to a convenient boundary definition.

Fig. 3.

Approximate extent of temple-and-pond-based agricultural settlements of the Angkorian and pre-Angkorian periods on the basis of an analysis of Landsat imagery and the spatial coverage of recent archaeological maps.


For the time being, perhaps the most satisfactory solution to the question of Angkor’s extent is therefore to take the infrastructural network as an indicator of cohesion in relation to the major monuments in the central 200–400 km2. The sheer scale of the network and its capacity to impact profoundly, regularly, and immediately on large areas of the inhabited landscape integrated an extended area into a single operational system within a circuit of great monuments and hilltop shrines located ≈20–25 km out from the center. Within this area of ≈1,000–1,200 km2, the northeast quadrant near Banteay Srei is largely empty of visible occupation features. The “boundary” of the urban complex of Angkor, as it can be loosely defined from the infrastructural network, encloses ≈900–1,000 km2 compared with the ≈100–150 km2 of Tikal (21), the next largest preindustrial low-density city for which we have an overall survey. Mirador, a Pre-Classic Maya urban complex, and Calakmul, a Classic site near Tikal, may be more extensive, but as yet we do not have comprehensive overall surveys for these sites; it is nonetheless clear that no site in the Maya world approaches Angkor in terms of extent (M. Coe, personal communication).

Notably, amongst a variety of significant outcomes, the mapping has resulted in the identification of two massive earthen structures, whose precise function remains unclear, east of the East Baray and to the southwest of Phnom Dei 1 (Figs. 4 and 5). Eventually, several thousand individual features (mostly ponds) were mapped as part of this process. A large number of these features do not appear in previous maps or within existing site inventories, including, for example, 79 linear features and 94 local temples. The class of “linear feature” is used here in preference to a specific identification as roadway or canal, because a careful analysis of the available remote sensing data, and of the radar data in particular, supports Groslier’s (1) observation that many of the linear features were multipurpose. In the extremely flat topography of the Angkor plain, an elevated roadway inevitably obstructed and/or channelled water on its upslope side, and the elevated banks of canals would have been used as convenient routes of transportation and locations for residential development, especially in view of the extremely waterlogged condition of the surrounding landscape for part of the year. In rare cases, the linear features are double-banked and were clearly designed and used for channelling water. In most cases, however, only one bank would have been required to channel water and/or create a road; thus the intended function of linear constructions cannot be categorically limited. The count of newly discovered temples represents only those that can be unambiguously identified as local temples because of their spatial patterning and/or verification from pedestrian survey, which has been carried out over part of the study area and is ongoing. The count is also provisional: at the time of writing, another 74 sites have been identified as likely temples but require field verification. The increased spatial resolution of the source data sets meant that features that were too small to be mapped using radar alone, such as occupation mounds, could be included in the new map of Angkor presented here (Fig. 2), which supersedes the mapping data produced in 2002. Some of the newly mapped features have been verified only through low-level aerial survey by using an ultralight plane. The task of verifying the thousands of features identified in the imagery on the ground has been a focus of GAP since 2002 and will continue to occupy field workers for many years to come. This notwithstanding, the new mapping work can generally be considered comparable in terms of methodology, content, and detail to the 1999 Pottier map, which it extends.

Fig. 4.

An arrangement of eight grid-like enclosures between the Angkor-Phimai Road and Prei Vihéar/Phnom Dei. Note that the road partially obliterates one of the enclosures, indicating that the structure is older than the (circa 11th- to 12th-century) road. Note the large Angkorian embankments running south from the Puok River toward the northeast corner of the West Baray, the size and great complexity of the infrastructure in the area, and also the numerous breaches of dykes and embankments by later watercourses.

Fig. 5.

An enclosed grid of mounds to the east of the East Baray. Note that it is isoclinal with Banteay Samrè and with the eastward extension of the northern wall of the baray, rather than with the baray or its outlet. Note also the extremely complex water management system in the area, including a northeast corner entry to the baray and the Krol Romeas distribution outlet from the center of the east bank of the East Baray into the Roluos River system.


Even on a quite conservative estimate, Greater Angkor, at its peak, was therefore the world’s most extensive preindustrial low-density urban complex. This has substantial implications for heritage management, as the well-preserved remains of Greater Angkor extend far beyond the designated World Heritage zone that surrounds the central temples. The scale of the site also has implications for its history and its demise. Angkor stands in a vast expanse of rice fields that would have required extensive forest clearance over the entire Angkor plain and up into the Kulen and Khror hills to the north. The new maps show that landscape modification at Angkor was both extensive and substantial enough to have produced a number of very serious ecological problems, including deforestation, overpopulation, topsoil degradation, and erosion. Whatever the functions of the infrastructural network, the impact of extensive clearance for rice fields, the economic and demographic consequences of constant modifications to the landscape, and unpredictable events such as flooding or warfare would potentially have been extremely serious for such an elaborate and interlinked system. The Siem Reap river is now incised 5–8 m into the Angkorian floodplain, and a major canal in the south of Angkor that postdates the 14th century CE is entirely filled with cross-bedded sands, indicating rapid movement of large quantities of sediment-laden water (8). There is also evidence, particularly in the newly mapped northern region, of ad hoc adaptations, breaches, modifications, and failures within this system, suggesting that it became increasingly complex and unmanageable over several centuries of development (Figs. 4 and 5). Current work by the GAP, including annual seasons of coring and excavations, is focused on dating those events.


From a theoretical point of view, the key issue with the current map is the common problem of chronological resolution within an extraordinarily large collection of temporally undiagnostic surface data (22). Although it is unrealistic to expect archaeologists to be able to excavate a substantial proportion of the newly mapped sites in the near future, efforts to attach temporal attributes (derived from inscriptions, artifacts, architectural analyses, absolute dating methods, and so on) to critically important features within the map data are ongoing as part of the GAP. From this research, the spatial and temporal development of urban form at Angkor will be amenable to modeling with a much greater degree of precision. Early settlement may have been along the lakefront and perennial water sources as Groslier suggested (1), a theory that has also been supported by recent excavations (23, 24). For the time being, the new mapping is consistent with Pottier’s (10) observation, based on his 1999 map of the south, that there appears to have been a gradual increase in occupation across all of the areas that were eventually inhabited over the course of about a millennium. This gradual process appears to have been punctuated by occasional, localized rapid development, for example in the Roluos area in the 8th and 9th centuries CE. However, this observation is based largely on the development of the major temple sites, and it remains to be demonstrated that the phenomenon is an accurate reflection of the nature of smaller-scale residential development. Ceramics found throughout Angkor are also consistent with Groslier’s (1) assumption that, at its peak in the 11th to 13th centuries CE, the entire settlement space as mapped was largely inhabited. At this stage, the only compelling evidence of the decline of an entire area during the Angkor era comes from the Roluos region, in particular the Bakong temple, where palynological studies (25) and archaeological excavations (23, 24) suggest a marked decrease in both agriculture and occupation in the late 9th and early 10th centuries. The Bakong moat fell into disrepair at around the same time. However, the spatial extent of abandonment beyond the temple, which saw very substantial redevelopment in the 12th century (26), cannot be precisely determined from the pollen data at this stage (D. Penny, personal communication).

Angkor meets the material requirements of Groslier’s proposed “hydraulic city” in that it possessed an immense, integrated, and highly complex system of water catchment, storage, and redistribution. The fact that the hydraulic city concept has previously been associated with the outmoded ideas of Wittfogel (27) is, as Pottier (15) points out, insufficient grounds for abandoning the entire concept and its various implications, especially in light of evidence emerging from recent archaeological research. Although ground-based archaeological investigations at Angkor are nowhere near as advanced as at comparable sites in Mesoamerica, for example, surface surveys (10) and excavations (8, 17, 23, 24) have consistently demonstrated that the features identified through remote sensing are of Angkorian origin and have the potential to provide crucial data about the rise and fall of urbanism in this area and the role of water management systems in that process.

Around the ponds and the local temples and on the occupation mounds it is now possible to see the fabric of residential life stretching around and far beyond the infrastructural network. The areal extent of the urban complex remains to be clarified by detailed analysis of its network connectivity. What is critical is that the present study has affirmed Groslier’s essential propositions about the structure of Angkor and now directs attention to his overall hypothesis that the collapse of Angkor was due to overexploitation of the landscape (1). The discussion of the implications must therefore be broadened well beyond the prevalent debate about whether or not the network was used to irrigate rice. As Groslier himself pointed out (1), this aspect of the hydraulic city was just one among many, even if it was the one that he elaborated on the most and that he clearly believed to be the most important.

Although it is important to recognize that certain elements of Angkor (for example, the temple of Angkor Wat) were never entirely abandoned, it is nonetheless very clear from the new maps that the settlement declined dramatically from a level of high complexity in the mid-second millennium AD, and that this constitutes a “collapse” by any standard definition (2830). By pursuing both the ideas and the methods proposed by Groslier combined with innovative techniques, such as airborne radar, the GAP will continue to investigate the degree to which the water management network and the environmental effects of the urban expansion of Angkor were implicated in that decline.

The size and settlement pattern of Greater Angkor have substantial implications for its management as a cultural resource. The well preserved remains of the urban complex extend far beyond the designated World Heritage zone that surrounds the central temples, highlighting the need to reappraise, in due course, how this remarkable heritage site is to be managed.

The outcomes presented here are also of considerable relevance for understanding the nature of urban settlements in Southeast Asia (31) and the analysis of past landscapes in the same region (32) and in particular for research on other temple complexes of the 1st millennium CE in the tropical world. Many of these, like Angkor and the Maya temples, may also lie at the center of previously undetected low-density urban settlements that are often obscured by vegetation or modern settlements. The key sites to be examined in South and Southeast Asia include Pagan in Myanmar, Anuradhapura and Pollonuruwa in Sri Lanka, Borobudur and Prambanan in Indonesia, Sukhothai in Thailand, Sambor Prei Kuk and Koh Ker in Cambodia, and My Son in Vietnam. Although there may prove to be no substantial occupation around the monuments at these sites, further analysis is critical, because similar discoveries in these locations would transform our understanding of their social, cultural, and environmental contexts in much the same way as has happened for the Maya settlements and now for Angkor. This, in turn, will provide a foundation for comparative studies of the great cities that emerged and then collapsed in fragile tropical ecosystems, an important and topical field of research that has received minimal attention thus far.


We thank Dan Penny, Terry Lustig, Andrew Black, and Michael Coe for their comments on drafts of this paper; Bruce Chapman of the Jet Propulsion Laboratory for his work on processing the radar data; and Donald Cooney, Eddie Smith, Alexandra Rosen, and the crew of the Angkor Ultralight Survey Group for their support of this project. Funding was principally from the Australian Research Council but also from the Mekong River Commission, the University of Sydney, l’École Française d’Extrême-Orient, the Authority for the Protection and Management of Angkor and the Region of Siem Reap, the Carlyle Greenwell Bequest (D.E.), and the Iain A. Cameron Memorial Travel Grant Fund (D.E.).


  • To whom correspondence should be addressed at:
    Archaeological Computing Laboratory, Madsen Building F09, University of Sydney, NSW 2006, Australia.


  • Author contributions: D.E., C.P., R.F., and M.B. designed research; D.E., C.P., S.H., I.T., and A.M. performed research; D.E., C.P., R.F., S.H., I.T., and A.M. analyzed data; and D.E. and R.F. wrote the paper.

  • The authors declare no conflict of interest.

  • This article is a PNAS Direct Submission.

  • ‡‡ Kummu, M., 5th World Archaeological Congress, June 21–26, 2003, Washington, DC, available at∼mkummu/publications/kummu_WAC_WashingtonDC_2003.pdf.

  • Abbreviation:
    Common Era.





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