Chauvet Cave (France)
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Chauvet Cave was rediscovered in 1994 after being concealed from prying eyes for more than 20,000 years. Featured in Werner Herzog's memorable documentary "Cave of Forgotten Dreams," Chauvet is home to the world's oldest paintings and is the finest collection of Paleolithic art ever discovered. The cave is in astonishingly pristine condition, containing not only the touching and reverent depictions of our Ice Age forebearers' natural world, but also physical traces of it. Tracks from cave bears extinct for thousands of years appear fresh, as do wolf prints accompanying those of a young boy. Scientists learned their lesson after visitors' breath caused mold to develop in nearby Lascaux, so it's extremely difficult to enter Chauvet. However, a replica of the cave is scheduled to open later this year.