The underground lake is approximately 800 feet long and 220 feet wide.
Anthodites found in the cave are needle-like crystals that grow in all directions, a rarity in geological formations.
During the Confederate era, the cave was mined for saltpeter to produce gunpowder.
In 1939, a complete Pleistocene-era jaguar skeleton was discovered deep within the cave system.
The cave temperature remains a steady 58 degrees Fahrenheit throughout the year regardless of external weather.
The cavern system was used as a public fallout shelter during the Cold War in the 1960s.
The Lost Sea Adventure is a cavern system in Sweetwater, Tennessee, featuring an underground lake recognized by the Guinness World Records as the largest of its kind in the United States. Visitors access the lake via a guided boat tour that navigates the subterranean waters. The cave, known historically as Craighead Caverns, contains significant deposits of anthodites, a rare type of cave flower crystal. The site served various historical functions, including a moonshine distillery, a saltpeter mine during the Civil War, and a fallout shelter. The tour route involves a steep walk down into the cavern, followed by a boat ride across the water surface. The lake is fed by an unknown source and remains at a constant temperature year-round. Wildlife within the cave system includes species of blind fish that have adapted to the lightless environment. The facility is privately owned and requires guided entry for all visitors.
The view from the boat ramp looking across the expansive, glass-like surface of the underground lake.
Wear comfortable, rubber-soled walking shoes as the cavern paths can be steep and slick.
Bring a light jacket, as the cave remains cool even during the peak of summer.
Arrive early in the day during weekends to avoid potential peak-hour crowds.
Attempting to explore beyond the guided tour path, which is strictly prohibited for safety and conservation.
Closed on Thanksgiving and Christmas Day.
No flash photography is allowed on the boat; remain seated during the water tour.
