Ancient Angkor, Cambodia's crown jewel, once reigned as the world's largest city with nearly a million residents. Recent temple discoveries shed light on the vast Khmer Empire's true scale and grandeur.

At the height of its glory, the city of Angkor in Cambodia was the world's largest metropolis, with a population of almost one million. Through the discovery of new temples, this scientific investigation reveals more about the extent of the Khmer empire. It also reveals the reasons for the decline of this civilization, whose medieval remains are now engulfed in thick vegetation. The study of the complex hydraulic systems built by the Khmers sheds light on the mystery surrounding the fall of the empire.