2. Death of Angkor Wat's Megacity

The experts continue their attempt to discover why Angkor suddenly collapsed, using a revolutionary technology called lidar to reveal the true scale and splendour of this abandoned megacity. Deep in the Cambodian jungle, they have discovered a sophisticated network of roads and canals that are the forgotten world of Angkor's greatest king, shedding new light on the dramatic events leading to the fall of the city.