(K. Brent Tomer),
It may not look like much now, but in the 12th century, Preah Khan of Kompong Svay (pictured) was part of the world’s largest urban settlement and one of its most powerful empires. Found beneath the forest floor near Angkor Wat using lidar (like radar, but with lasers), these cities of the Khmer Empire show complex water systems built centuries before the underlying technology was believed to have existed, as well as highways connecting major settlements. The lack of evidence of a substantial relocated population nearby casts doubt on the widely accepted theory that the Khmer Empire collapsed when the Siamese invaded. More maps will be published in the coming months.