Inner Space Cavern
Inner Space cavern was discovered by a Texas Highway Department core drilling team in the Spring of 1963. Six inch core samples were taken to determine if the ground was stable enough to support a large highway overpass. As they were drilling one of the test holes, the bit suddenly dropped 26ft. and the highway crew knew there was something down there besides rock.
Cumberland Caverns is one of the most extensive known caves in Tennessee. Portions of this caving system were originally known as Higgenbotham Cave and Henshaw Cave. Considerable exploration of previously unseen sections along with integration of the two caves substantially enlarged the Caverns to the more than 32 miles that can be toured today.