Jewel Cave National Monument

Cave in the Black Hills of South Dakota, USA

Jewel Cave National Monument contains Jewel Cave, currently the fifth longest cave in the world and second longest cave in the United States, with 220.33 miles (354.59 km) of mapped passageways as of July 2025. It is located approximately 13 miles (21 km) west of the town of Custer in the Black Hills of South Dakota. Jewel Cave became a national monument in 1908, becoming the first national monument established for the protection and preservation of a cave.

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