Spelunk'd

Until 1986, Lechuguilla Cave was a mere footnote in the story of Carlsbad Caverns National Park, New Mexico. After hearing air moving below rubble on the cave floor, cavers gained permission from the National Park Service to dig through the rubble, and on May 26, 1986, they literally unearthed large walking passages branching from the cave. Pictured above is a room in Lechuguilla called The Chandelier Ballroom, which features the largest known gypsum stalactites in the world. Hear more about its discovery and the exploration of Lechuguilla on this week's show, Extreme Geology.