Blanchard Springs Caverns

Blanchard Springs Caverns is a cave system located in the Ozark–St. Francis National Forest in Stone County in northern Arkansas, 2 miles off Highway 14 a short distance north of Mountain View. It is the only tourist cave owned by the United States Forest Service and the only one owned by the Federal government outside the National Park System. Blanchard Springs Caverns is a three-level cave system, all of which can be viewed on guided tours.

The Dripstone Trail runs through the uppermost level of caverns for about a half-mile and opened in 1973. The Discovery Trail opened in 1977 and loops through a 1.2-mile section of the cavern, descending to the lower level of the cave, 366 feet underground, as well as to the Natural Entrance, about 100 feet below ground at that point, following the stream bed of the springs that created the cavern.

Source: Wikipedia