Jewel Cave National Monument

Jewel Cave National Monument is home to the fifth longest cave in the world, with over 220 miles of mapped passageways located approximately 13 miles west of Custer in the Black Hills of South Dakota. Named for the calcite crystals that cover many of its walls, the cave became a national monument in 1908 — the first in the U.S. established specifically to protect a cave. The National Park Service offers four guided tours: the Scenic Tour, a paved, elevator-accessed loop through the cave's central passages; the Discovery Tour, a short accessible introduction; the Historic Lantern Tour, a lantern-lit journey through the earliest-discovered sections; and the Wild Caving Tour, an adventurous crawl through undeveloped passages. Advance reservations on Recreation.gov are strongly recommended. Above ground, the 1,279-acre monument features ponderosa pine forest, open meadows, and two hiking trails with views of Hell Canyon and the southern Black Hills. Wildlife includes bighorn sheep, mule deer, and mountain lions.