The temple of Angkor Wat in Cambodia is a dazzling architectural masterpiece built at the zenith of the Khmer empire by its power-hungry ruler Suryavarman II during his reign from AD 1113-1149. Providing a spectacle of beauty, wonder, and magnificence, the main temple –with its famous lotus-bud towers – spans a mighty 215m by 186m, and rises more than 60m above the surrounding land, while its moated enclosure walls ring an area of 1,500m by 1,200m. Said to be the world’s largest pre-20th-century religious building, Angkor Wat dwarfs even the biggest Sumerian ziggurat, and makes Karnak’s Temple of Amun and the citadel at Mohenjo-daro on the Indus look like village shrines.

Archaeologists, especially from France, have studied Angkor Wat since the late 19th century. Much of their focus has been on its art, architecture, epigraphy, iconography, and ritual functions. One cannot blame them, faced as they have been with a site of overwhelming magnitude. But, as a new generation of researchers is demonstrating, the temple simply cannot be understood in isolation: it needs to be placed in the wider context of the area that lies all around it.
For the past 20 years, a series of remote-sensing projects and extensive field research – started by Christophe Pottier, and expanded by Roland Fletcher and Damian Evans – have sought to gain information through wider surveys of the area. This work revealed that, unlike today, Angkor Wat was not originally in the heavy jungle, but was near the middle of the huge, low-density urban complex known today as ‘Greater Angkor’, which covered an area of around 1,000km2, and contained an estimated 750,000 inhabitants. In this sense, Greater Angkor resembled the Classic Maya centres like Tikal in Guatemala and Caracol in Belize – but was immensely larger. In the course of their work, the researchers located evidence for canals, roads, ponds, housemounds, hundreds of small shrines, and many thousands of bunded rice fields (or fields surrounded by low, narrow banks).


However, the dense forest hampered their admirable surveys, especially around Angkor Wat itself, at the heart of the Angkor World Heritage Archaeological Park. So, in 2012, Damian Evans and Roland Fletcher launched a new project using airborne LiDAR scanning, a technique that is able to ‘see’ through the jungle (see box on p.19). In addition, a sterling team of specialists drawn from many countries, spanning Europe, Australia, the United States, and Cambodia, has been undertaking walk-over Ground Penetrating Radar (GPR) surveys and targeted excavations. This current work completely redefines Angkor Wat’s landscape, and is finally unlocking the secrets of the site. But before we broaden our view to discover the latest findings, we must return to within the enclosure of Angkor Wat itself.
Heaven on earth
To the Khmer, Angkor Wat was heaven on earth. Every detail of this extraordinary shrine reproduced their celestial world in a terrestrial mode. King Suryavarman’s people believed that the world consisted of a central continent known as Jambudvipa, with the cosmic mountain of Meru rising from its centre. Angkor Wat’s highest tower represents Meru, while its four lesser towers depict the mountain’s smaller peaks.
The great enclosure wall around the temple represents the mountains at the edge of the world, the surrounding moat the Sea of Milk around Meru where gods and demons churned ambrosia. Originally dedicated to the Hindu Protector Vishnu, Suryavarman II used Angkor Wat as the place where he, as divine ruler, communicated with the gods. When he died, his remains were placed in the central tower, so that his soul entered his divine image and made contact with the royal ancestors. Here he became as one with Vishnu, master of the universe.
A carefully organised workforce, brought in from all over the empire, fuelled by enormous food surpluses, notably rice grown in the surrounding region and fish from the Tonle Sap lake, built the complex for their divine ruler. Suryavarman and his successors presided over a civilisation that carried the cult of divine monarchy, luxury, and wealth to staggering heights, with Angkor Wat as the apogee of Khmer architecture. Metre after metre of exquisite bas-reliefs at Angkor Wat show Suryavarman on a throne receiving high officials. He progresses on an elephant accompanied by the high priest and his generals. The court rides with him through a forest with noble ladies in litters, everyone protected by heavily armed soldiers. Scenes of battles and celestial maidens naked to the waist adorn entire walls. Slender and sensual, they wear skirts of sumptuous fabric and rich ornaments, their dances symbolising the delights of paradise promised to the ruler after his death. Angkor Wat is a monument of architectural genius, its decoration never fully completed, and like all great shrines it was modified and reused.

Inscriptions tell us that thousands of people staffed the temples, with many thousands more growing and delivering food within Greater Angkor to support the temple staff – a huge maintenance cost. But the religious utopia was not to last. Angkor began to dissolve after the 13th century due to combination of severe climate change, endemic warfare, and the new maritime trade networks. The Khmer state endured, by shifting its capital to the region around Phnom Penh. As for the magnificent Angkor Wat, it became a Buddhist temple, as it has been ever since.
How did the site work?
Clearly the great temple of Angkor Wat was of huge importance to its people, but how exactly did it work, or fit within the wider landscape? Throughout the 19th and 20th centuries, the standard view was that Angkor Wat was a ‘temple-city’, and the capital of the Khmer Empire in the 12th century. Its large walled and moated enclosure was thought to have housed a densely populated settlement – the bulk of the Angkor area’s urban population – including the elite members of the ruler’s palace, with an agricultural hinterland of isolated villages and forest outside the moat.


Moreover, according to earlier scholarship, Angkor Wat was just one town in a succession of small walled and/or moated capitals, each set neatly around great state temples. These Angkorian state temples with their presumed enclosures, of which a total of seven had been identified, were thought to culminate with the late 12th-century 9km2 city of Angkor Thom (meaning ‘Great City’ in Khmer). The almost (but not quite) as famous Angkor Thom lies about a kilometre to the north of Angkor Wat, and was built by Jayavarman VII (r.1181-1218). Its dark and foreboding walls hide architectural beauties, such as the Bayon Temple, that almost (but not quite) rival those of Angkor Wat.
Were these long-held assumptions really so? With the fall of empire, many of the area’s secrets were lost to both time and encroaching vegetation. The launch of the 2012 LiDAR research, directed by Damian Evans for KALC (the Khmer Archaeology LiDAR Consortium), and in collaboration with Tan Buon Suy of the APSARA National Authority (the Cambodian body responsible for Angkor), has made possible the virtual ‘removal’ of the vegetation cover. This space-age technology has allowed the accurate mapping of Angkor Wat – both its temple enclosure and its moat – together with large tracts of the central urban area around the temple. For the first time, and in a way that was unimaginable even ten years ago, archaeologists are rewriting the history of Angkor Wat.
Rewriting the textbooks
The results from the new project have come in at breakneck speed. At Angkor Wat itself, the LiDAR survey revealed that the temple complex was far larger and more complicated than had previously been imagined. In addition to the temple’s huge main moated central enclosure, LiDAR identified a large eastern extension, thought to be an administrative or habitation zone, together with a perplexing and unique area just south of the moat. The latter area consists of four major blocks, each containing rectilinear ‘spirals’ made of linear banks separated by channels with associated ponds. Perhaps they were raised fields – like those found in some pre-Columbian American landscapes – used for growing aromatics, such as sandalwood trees on the mounds and lotus plants in the channels, used in temple rituals. They could even have served as ornamental gardens, which would have been far bigger than anything seen in Europe until the 18th and 19th centuries.

Moving to Angkor Wat’s main enclosure wall, this laterite and sandstone edifice is over 4m high and 1m thick, and contains four formal entrances to the temple complex. It was built in the 12th century as part of the original layout of the temple. Here the team uncovered two previously well-hidden secrets. First, GPR survey just inside the outer west gate of Angkor Wat, together with subsequent excavations, revealed the foundations of two cruciform structures. However, they had been demolished and partially buried under the outer enclosure wall and the main causeway. Why? Their footprints suggest they had once been shrine towers similar to those found in the main Angkor Wat temple. Since they had been demolished when the outer wall was built, the team suggests they represent an as-yet unique temporary shrine that was probably in use while the main temple was being built – and is just one part of the temple’s process of continual modification that continued until at least the 17th century.

Second, careful archaeological detective work showed that the wall had been systematically modified – but for defensive purposes. This discovery came as a shock since no historical record has ever mentioned, or even whispered of, a later defensive function for Angkor Wat. The team suggests it must have occurred late in Angkor’s history, either between 1297 and 1585, or between 1585 and the 1630s, when the neighbouring state of Ayutthaya was on the ascendant.
Within the enclosure itself, airborne LiDAR identified yet more: a formal grid of roads, mounds, and associated small ponds (typically 20-30m across, and probably originally used for drinking and washing) surrounding the great temple. This mound and pond system maintained a housing tradition that had already been in place for 600 years in Cambodia, illustrating how the traditional long-term organisation of Khmer life persisted, even in the shadow of the great towers rising nearby.
Mega-city in the jungle
Then LiDAR revealed something else, something quite unexpected. The survey showed that the road grid of central Angkor originated in Angkor Wat half a century before Angkor Thom was even built. Indeed, the grid extends far beyond Angkor Wat and Angkor Thom, surrounding all the great temples of Angkor, and tying into a road and canal network that stretched out across the old, sprawling suburbs of Greater Angkor where most people lived. The archaeologists came to the stunning realisation that Angkor Wat, Angkor Thom, and the other ‘temple cities’ were not separate and successive cities, as has been assumed by generations of researchers. Rather, they should be seen as a succession of connected and interrelated additions to the central urban area.
Moreover, this new work indicates that the wider area was no less urban than the central area, and that the old dichotomy of Khmer holy city/outlying countryside is false. Instead, the whole of Greater Angkor should be regarded as the ‘city’ – somewhat akin to New York City’s relationship to the central urban area of Manhattan with St Patrick’s Cathedral, or as Greater London is to its central City of London with St Paul’s Cathedral. Indeed, Greater Angkor is just like the present-day desakota of Southeast Asia and China – those gigantic rural-urban cities spread across extensive areas of rice fields. This low-density urban pattern is in sharp contrast to the typical (European or Near Eastern) archaeological ‘compact city’, where the city is seen as a discrete entity, often walled, and in contrast to its rural hinterland.

Sensing remote lives
A new and unexpected picture is thus emerging of a once deeply interconnected urban landscape, long hidden by the voracious jungle. But how did it all fit together? Who lived where, how, and in what numbers? Surely the ethereal temple complex of Angkor Wat was the seat of the wealthy elite, with the rest living outside its walls? Even this long-held image crumbled in the wake of the new research.
Within the temple complex, the team identified potsherds and traces of domestic occupation that chronicle relatively modest dwellings, mainly of perishable materials. It is as though the people living within the temple complex were not the rich and privileged, but more likely temple staff (including priests, dancers, and officials). In terms of how many people lived within the enclosure, the team identified a grid pattern of about 250-300 ponds within its walls using LiDAR, core borings, ground survey, and selective excavation. This pond-count (where previously only a handful of these household ponds had been identified), together with calculations extrapolated from reports of a Chinese visitor in 1295/1296, suggests that around 4,000 people might once have lived within Angkor Wat’s main enclosure.


Drawing on an inscription from another late 12th-century temple, which details precise numbers of people involved in making the temple function, the team has calculated the likely numbers involved with the running of Angkor Wat. It seems the whole temple staff feasibly numbered around 25,000 people, which means many more staff members would have lived outside the temple complex, albeit probably quite close to the temple. Given the inscription goes on to state that five-times more people delivered food and produce to this staff, the team has estimated that another 125,000 people, most of them probably living and working in the outer suburbs, would have contributed to the running of the temple. These are huge figures, and give one a hitherto unsuspected sense of the scale of the Angkor Wat operation.

For this supply of food to work reliably, Angkor needed a massive water-management system to stabilise the water supply for farming and prevent flooding. That sophisticated system of canals, ponds, and reservoirs was only fully recognised during remote-sensing work undertaken at the start of this century. We now know that Angkor Wat, and the other major shrines within central Angkor, lay at the heart of a huge network that managed, stored, and dispersed water from three small rivers down through the city and into the Tonle Sap lake. The scale of the waterworks is truly staggering. One of the reservoirs – the West Baray, about 2km west of Angkor Wat – is about 8km long and 2km wide, and was fed by water diverted from rivers to the north. Meanwhile, another embankment that steered water back across the landscape to the south of the baray was at least 40km long.
Revolutionary research
As well as revolutionising our understanding of the splendour, scale, and complexity of Angkor Wat, the contribution of LiDAR and conventional archaeological methods is transforming our understanding of the region of Angkor, revealing a vast and interconnected urban landscape. The research in Angkor also has significant implications for archaeologists studying pre-industrial cities and towns everywhere. For generations, we have tended to think of cities as dense agglomerations of people living cheek by jowl. Yet remote-sensing and especially LiDAR, both at Angkor and at Maya cities in Central America, are showing just how dispersed many early cities were, with denser central areas surrounded by extensive outlying suburbs, just like many modern cities. Through archaeology, the nature of the city before the Industrial Revolution is being redefined.
Using LiDAR is expensive and very fine-grained research, but it epitomises a new era of long-term team research in archaeology, when the symbol of the archaeologist will not be just a spade, but also remote-sensing apparatus, whether used from satellites, planes, helicopters or drones. The vast quantity of precise new survey data from Angkor is revealing the magnitude of the Khmer achievement, which certainly rivalled that of the Ancient Egyptians and the Romans too. As Roland Fletcher and his colleagues remark: ‘The results are a profound display of the power, relevance, and necessity of archaeology.’ To which we would add a fervent amen!




DOING LiDAR
LiDAR – or Light Detection And Ranging – is a form of laser-scanning, originally developed in the 1960s, and initially used in meteorology. Over the past decade or so, archaeologists have begun routinely to use the technology, drawn to its ability to capture extraordinarily accurate, high-resolution, 3D data. It works by using light sensors to measure the distance between the sensor and the target object. This results in a series of ‘dots’ that computer wizardry is able to convert into a 3D mesh.
The principle behind LiDAR is quite simple: light travels very fast – about 300,000km per second, 186,000 miles per second, or 0.3m per nanosecond, and LiDAR measures the time it takes for the light to return to its source. Naturally, the equipment required to measure this has to operate extremely fast, and it is only with advances in modern computing technology that this has become possible.

Archaeologists may use LiDAR on the ground, where it is able to record buildings or monuments in extreme detail. But, as at Angkor, it can also be used from an aircraft (the team used a helicopter), with the sensor recording all that lies on the surface of the ground, whether buildings, vegetation, or the earth itself. Indeed, at Angkor, LiDAR has, for the first time, allowed the easy and efficient mapping of terrain normally obscured by dense and protected vegetation.
Given the accuracy and speed of data-capture, LiDAR is far more cost-effective than traditional survey methods. It is also non-destructive and chronologically informative. Is this the future of aerial archaeology? Certainly fieldworkers in many parts of the world think so: witness recent LiDAR surveys at Caracol in Belize and, last year, at the pre-Classic Maya settlement at El Mirador, Guatemala, or the pioneering survey of the grounds of the colonial Wye Hall Plantation, near Chesapeake Bay in the United States – once owned by William Paca, Governor of Maryland, one of the signatories to the Declaration of Independence.
Further reading A series of detailed reports on the new research appears in a special section of Antiquity, vol. 89, no. 348, December 2015.
ACKNOWLEDGEMENTS CWA thanks Professor Roland Fletcher of the University of Sydney for his assistance with this feature. We also acknowledge and thank Damian Evans, Christophe Pottier, Miriam Stark, Alison Carter, Dougald O’Reilly, Chhay Rachna, Heng Piphal, Till Sonneman, David Brotherson, Tom Chandler, and Michael Dega for contributions to the work and for illustrations. Further thanks go to Antiquity for providing project images.
Images: Antiquity.