Shelta Cave is a 2,500 feet (760 m) long underground cave and lake located in Huntsville, Madison County, Alabama. It is described as one of the most biodiverse caves within the Appalachian Mountains. The cave is currently owned and managed as a nature preserve by the National Speleological Society, with their main offices directly above the cave. It was declared a National Natural Landmark in October 1971.
This cave was an underground bar and dance hall in the early 1900s. The cave is open to members of the NSS during certain times of the year to minimize the impact on the biota. There are now three sinkhole entrances. The lake can be as large as 7 acres (2.8 ha) during the winter and early spring rainy season. Other times of the year, the lake bed is exposed.