Rushmore Cave into a rock known as limestone. The cave has a cornucopia of rooms including the Entrance Room, Post Office, Image Room, Big Room, Fairyland, Rope Room, Geode Room, The Rouge Room (Party Room), Arrowhead Room, and the Floral Room. The cave also includes boxwork and many dripstone formations including stalactites, stalagmites, columns, helictites and flowstone. Rushmore Cave Rushmore Cave is the closest show cave to Mount Rushmore National Memorial in the United States. It contains a wide variety of natural formations. It is the ninth longest cave in South Dakota. It measures a distance of . It was discovered in
Mount Rushmore in popular culture secret base inside Mount Rushmore. In "", it is the secret base of operations for the protagonists. In the film, the base, along with the sculptures on the surface, are severely damaged in a suicide bombing by Michael Moore. In the universe of the "Ben 10" franchise, Mount Rushmore is the location of the main Plumbers (a sort of intergalactic police force) complex, and plays a key role in multiple episodes of the series, including "Secrets," "Truth", the "Ben 10,000" episodes, and "Ben 10 vs. The Negative 10." The monument is inadvertently destroyed by Upchuck in the latter episode, during