The Namib Sand Sea, home to 350-foot-tall sand dunes, receives so little rainfall that it is almost uninhabitable. Scholars believed it had been this way for millions of years—but this turns out not to be the case. New research at a site called Narabeb identified layers of mud beneath the sand that were deposited by an ancient freshwater lake. Fragments of stone tools found nearby suggest that early humans visited Narabeb occasionally between 200,000 and 20,000 years ago.

Excavations outside the Archbasilica of St. John Lateran in Rome revealed walls of a papal palace dating to the 9th century a.d. The sprawling complex was founded in the 4th century a.d. after the Roman emperor Constantine converted to Christianity. It was expanded and remodeled over the following centuries. The Lateran palace was the home of the papacy until the 14th century, when it briefly moved to Avignon, France, before relocating to the Vatican, where it remains today.

Between a.d. 600 and 1000, the Maya city of Cobá was inhabited by 50,000 people and was home to Nohoch Mul, the second tallest pyramid on the Yucatán Peninsula. Off a causeway connected to the temple, archaeologists recently discovered a panel including 123 Mayan glyphs carved into the rock floor of a sacred pool. These glyphs describe the founding of a town called Keh Witz Nal on May 12, a.d. 569. They also reference a previously unknown Maya ruler named K’awill Ch’ak Chéen.