
Unprecedented details of the medieval cities hidden underneath the jungle near Angkor Wat, Cambodia, have been revealed using lasers, shedding new light on the civilisation behind the world's largest religious complex.

While the research has been ongoing for several years, the new findings reveal that the scale of the Khmer Empire's urban sprawl and temple complexes are significantly bigger than previously thought.

The research, drawing on airborne laser scanning technology known as lidar, will be unveiled in full at the Royal Geographic Society in London on Monday by Australian archaeologist Damian Evans.

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Airborne laser scanning technology (lidar) was used to create aerial images of Cambodia in 2015. Above, one of the images showing Preah Khan of Kompong Svay, a 120sq km area near Angkor Wat

Lidar equipment was mounted on helicopters (pictured). The research has been ongoing but new details have recently been revealed

‹ Slide me › Using lidar technology, archaeologists are able to strip away the vegetation. Above, Choeung Ek pictured with (left) and without (right, using lidar) vegetation

A previous major scan was conducted in 2012 but the 2015 scan was much more extensive, covering a much bigger area (pictured)

Evans told AFP: 'We always imagined that their great cities surrounded the monuments in antiquity.

'But now we can see them with incredible precision and detail, in some places for the very first time, but in most places where we already had a vague idea that cities must be there.'

Angkor Wat, a Unesco World Heritage site, is considered one of the ancient wonders of the world.

It was constructed from the early to mid 1100s by King Suryavarman II at the height of the Khmer Empire's political and military power and was among the largest pre-industrial cities in the world.

But scholars had long believed there was far more to the empire than just the Angkor complex.

The huge tranch of new data builds on scans that were made in 2012, which confirmed the existence of Mahendraparvata, an ancient temple city near Angkor Wat.

New images from the survey show ancient cities near Angkor Wat were much bigger than previously thought. Above, a shaded relief map of the terrain around the central monuments of Sambor Prei Kuk

The information has helped archaeologists to map out the area and will help increase the accuracy of future digs. Pictured above, terrain in the mountains to the north of Angkor

But it was only when the results of a larger survey in 2015 were analysed that the sheer scale of the new settlements became apparent.

To create the maps, archaeologists mounted a special laser on the underneath of a helicopter which scans the area and is able to see through obstructions like trees and vegetation.

Much of the cities surrounding the famed stone temples of the Khmer Empire, Evans explained, were made of wood and thatch which has long rotted away.

He said: 'The lidar quite suddenly revealed an entire cityscape there with astonishing complexity.

'It turned out we'd been walking and flying right over the top of this stuff for ten years and not even noticing it because of the vegetation.'

Among the new scans already published are a detailed map of a huge city complex surrounding the stone temple known as Preah Khan of Kompong Svay, a series of iron smelting sites dating back to the Angkor era and new information on the complex system of waterways that kept the region running.

It was only when the results of a larger survey in 2015 were analysed that the sheer scale of the new settlements became apparent. Above, the iron smelting sites in Preah Vihear province

The new data also maps out the full extent of Mahendraparvata - information that will make future digs much more accurate and less time consuming.

Evans said: 'What we had was basically a scatter of disconnected points on the map denoting temple sites. Now it's like having a detailed street map of the entire city.'

He added that further maps will be published in the coming months on angkorlidar.org.

Long Kosal, a spokesman for the Apsara authority, the government body that manages the Angkor complex, said the lidar had uncovered 'a lot of information from the past.'

He told AFP: 'It shows the size and information about people living at those sites in the past.'

However, further research was now needed to capitalise on the finds.

While the Khmer Empire was initially Hindu it increasingly adopted Buddhism and both religions can be seen on display at the complex.

Angkor Wat is visited by hundreds of thousands of visitors a year and remains Cambodia's top tourist attraction.