Shooting a million laser beams every four seconds from the bottom of a helicopter, the lidar technology (which stands for light imaging detection and ranging) allows a kind of virtual deforestation to take place, stripping away the tree canopy to reveal what lies beneath on the forest floor.
The findings were a revelation. The scanning exposed a topography inscribed with a precise network of furrows and mounds, the bones of the city etched into the landscape.
“On the ground you just see lumps and bumps,” says Evans, “but this aerial view shows a very sophisticated system of road networks, planned neighbourhoods and intricate waterworks. Angkor was a work of geoengineering on an unparalleled scale.”