Bluespring Caverns is the home of Myst’ry River a rather hokey name for the longest subterranean river in the United States, running about 21 miles.
Take a subterranean river tour on a specially designed 17 person flat-bottomed boat. The tour, which lasts an hour, travels about 1 ¼ quarter miles along the underground river.
The boat tour follows the river’s twists and turns moving through passageways whose walls are coated with a fine film of mud. Overhead, water occasionally drips from stalactites.