Clarks Cave

Clarks Cave is a cave in Bath County, Virginia. It is a major archeological site, and was mined for saltpeter in the 1800s. The cave is 6.43 miles, and has 6 entrances. It is considered an excellent example of a joint-controlled cave, with an extensive maze of passages than run along joints in the rock, a Lower Devonian limestone.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).