Melbourne: A lost medieval city that thrived on a mist-shrouded Cambodian mountain 1,200 years ago has been found using revolutionary airborne laser technology, according to a report.
The stunning discovery of Mahendraparvata includes temples hidden by jungle for centuries that archaeologists believe have never been looted, the Sydney Morning Herald reported today.
The expedition used an instrument called Lidar — light detection and ranging — strapped to a helicopter pushing through landmine-strewn jungle, swollen rivers and bogs criss-crossing the Phnom Kulen mountain, 40 kilometres north of Angkor Wat, the largest Hindu temple complex in the world.
The Lidar technology peeled away the jungle canopy using billions of laser pulses, allowing archaeologists to see for the first time structures that were in perfect squares, completing a map of the city which years of painstaking ground research had been unable to achieve.
The instrument provided data uncovering over two dozen previously unrecorded temples and evidence of ancient canals, dykes and roads, the report said.
The research revealed that the discovered city, Mahendraparvata, founded the Angkor Empire in 802AD and existed 350 years before Angkor Wat, the Hindu temple that has captivated interest across the world and is visited by more than 2 million people each year.
French-born archaeologist Jean-Baptiste Chevance, director of the Archaeology and Development Foundation in London, who led the expedition, said it was known from ancient scriptures that a great warrior, Jayavarman II, had a mountain capital, "but we didn't know how all the dots fitted, exactly how it all came together.
"We now know from the new data the city was for sure connected by roads, canals and dykes," he said.
Damian Evans, director of the University of Sydney's centre in Cambodia and a co-leader of the expedition, said there might be important implications for today's society.
"We see from the imagery that the landscape was completely devoid of vegetation," he said, adding "One theory we are looking at is that the severe environmental impact of deforestation and the dependence on water management led to the demise of the civilisation... perhaps it became too successful to the point of becoming unmanageable".
Locations of almost 30 previously unidentified temples have now been confirmed using the Lidar data.
The discovery is set to be published in the Proceedings of the National Academy of Sciences in the United States and expected to prompt scientific excavation of the most significant sites by archaeologists seeking to discover what life was like for a civilisation about which very little was known, including why it was abandoned to the forest.
It will also allow archaeologists and historians to learn more about the evolution of Angkor, the enormous political and religious empire that dominated most of south-east Asia for 600 years, the report said.