Lascaux Cave, France

Photograph by Sisse Brimberg

Containing some 600 paintings, Lascaux Cave in France's Dordogne River Valley is home to perhaps the world's most incredible array of Upper Paleolithic art. Prehistoric artists created the depictions of bulls and other animals on the cave's calcite walls more than 17,000 years ago. The cave—and its artwork—was discovered by a group of teenagers in 1940.