The city, which predates the famous Angkor Wat by several centuries, indicates the previously known temple complex was a part of a much larger, sprawling city rather than a walled-in city.
A study led by the Archaeology and Development Foundations Phnom Kulen program and published in the Proceedings of the National Academy of Sciences relied on LiDAR -- light detection and ranging -- airborne laser scanning to across a swath of about 140 square miles in northwestern Cambodia.
The images revealed, "with exceptional clarity," "a vast, low-density urban periphery stretching far beyond the major Angkorian temples."
Most of these structures were only revealed thanks to LiDar's "unparalleled ability to penetrate dense vegetation cover and map archeological remains on the floor," the researchers said.
In video footage of the team trooping through the jungle, only a few stones are visible, as much of the archaeology is encased in the ground.