Jewel Cave National Monument
Custer, SD · Black Hills
Jewel Cave earns its name underground, where calcite crystals known as nailhead and dogtooth spar glitter across walls that wind on for more than 220 mapped miles, making this the second longest cave in the United States and a place geologists are still actively surveying. The lit Scenic Tour drops you in by elevator to a half mile loop past draped flowstone, delicate boxwork, and ribbons of formation the rangers call cave bacon, while the Historic Lantern Tour hands you a real lantern and walks the rough, early passages the way the first explorers saw them. It is a working scientific frontier dressed as a sightseeing stop, a quiet 13 miles west of Custer in the Black Hills.





