Nabta Playa: The Saharan Stone Circle Older Than Stonehenge Still Baffles Experts

Nabta Playa in Egypt is a monumental stone structure predating both Stonehenge and the Giza pyramids, increasingly dubbed the "Stonehenge of the Sahara." The site sits in what is now arid desert, but the region was far wetter when it was built. Archaeologists have yet to determine its purpose.