Big Bone Cave is a cave located in Van Buren County, Tennessee, in the community of Bone Cave. It is notable both for its history and current recreational use. It is listed on the National Register of Historic Places and is a 334-acre (1.4 km2) State Natural Area managed by Rock Island State Park. It is named for the discovery of the bones of a giant ground sloth in 1811. The cave was operated as a saltpeter mine, notably during the War of 1812 and the American Civil War. A variety of natural remains and human artifacts has been well preserved in the dry atmosphere of the cave. The cave is the 7th longest mapped cave in Tennessee.