Revealed: Cambodia's vast medieval cities hidden beneath the jungle

Laser technology reveals cities concealed under the earth which would have made up the world’s largest empire in 12th century.

Archaeologists in Cambodia have found multiple, previously undocumented medieval cities not far from the ancient temple city of Angkor Wat, the Guardian can reveal, in groundbreaking discoveries that promise to upend key assumptions about south-east Asia’s history.

The Australian archaeologist Dr Damian Evans, whose findings will be published in the Journal of Archaeological Science on Monday, will announce that cutting-edge airborne laser scanning technology has revealed multiple cities between 900 and 1,400 years old beneath the tropical forest floor, some of which rival the size of Cambodia’s capital, Phnom Penh.

Some experts believe that the recently analysed data – captured in 2015 during the most extensive airborne study ever undertaken by an archaeological project, covering 734 sq miles (1,901 sq km) – shows that the colossal, densely populated cities would have constituted the largest empire on earth at the time of its peak in the 12th century.Evans said: “We have entire cities discovered beneath the forest that no one knew were there – at Preah Khan of Kompong Svay and, it turns out, we uncovered only a part of Mahendraparvata on Phnom Kulen [in the 2012 survey] … this time we got the whole deal and it’s big, the size of Phnom Penh big.”

Evans obtained European Research Council (ERC) funding for the project, based on the success of his first lidar (light detection and ranging) survey in Cambodia in 2012.

That uncovered a complex urban landscape connecting medieval temple-cities, such as Beng Mealea and Koh Ker, to Angkor, and confirmed what archaeologists had long suspected, that there was a city beneath Mount Kulen. It was not until the results of the significantly larger 2015 survey were analysed that the size of the city was apparent.

Experts in the archaeological world agree these are the most significant archaeological discoveries in recent years.