How LIDAR Scans Reveal Angkor's Hidden City

For years scientists have been marching through the forests and mud to find depression spots in the earth. They now have been equipped with an aerial survey device that can pin point spots on the earth and eliminate nature to see what the ground looked like years before our time. This video shows ancient cities even that have been built over 900 years ago and now we can get an idea for how big they actually were due to the depression spots they made in the earth.