Ruby Falls
Show Cave · Chattanooga, Tennessee
A 145-foot waterfall in a chamber more than a thousand feet inside Lookout Mountain — the deepest and tallest waterfall open to the public underground anywhere in the United States. It was found by accident in 1928, when Leo Lambert was drilling a lift shaft to reach a cave the railway had sealed and broke into a passage nobody knew existed; he crawled along it for hours and came out in front of the falls, and named it after his wife. Visitors now descend by lift and walk the last half-mile through the same passage.
1720 South Scenic Highway, Chattanooga, Tennessee, 37409, United States
Open daily year round on timed guided tours, generally from mid-morning into the evening with extended summer hours. Closed Thanksgiving and Christmas Day. Book timed tickets in advance — slots sell out in summer and on autumn weekends.