Using lidor, a sophisticated remote sensing technology that is similar to radar, an international team of archeologist headed by the University of Sydney’s Dr. Damian Evans, uncovered a hidden city around the Cambodian temple of Angkor Wat. In what is now a dense jungle, the lidor (which they used by flying over the area in helicopters) uncovered roads, temples and even a hydraulic water system that once sustained a city that was the greatest medieval complex in the world.
At its peak in the 12th century, the city of Angkor covered 1,000 square kilometers. London only reached that size 700 years later.
Angkor was the capital of the Khmer empire, which encompassed all of present-day Cambodia and much of Vietnam, Laos, Thailand and Myanmar. The city of Angkor had about a million residents.
The largest structure of Angkor is Angkor Wat, which is still uncovered and attracts millions of visitors a year. Angkor Wat covers an area four times larger than the Vatican.
The hydraulic water system, which emerged as the most staggering achievement of this ancient culture, harness monsoon waters in complex network of canals and reservoirs. The harvested water provided food security for the residents of the city, and made the city’s noble class fabulously wealthy. They used this wealth to build some of the most amazing temples on earth. One temple contained so much gold that its value to day would have been $3.3 billion.
Disaster struck for the Khmer empire when they paid more attention to building temples than to maintaining the hydraulic network. And just like in some modern cities, when the infrastructure crumbled, the populace suffered. Eventually, large climate shifts across southeast Asia brought the city down. Tree ring samples recorded sudden fluctuations between dry and wet conditions. Lidar maps show a huge flood that must have overcome the city’s water network.