The Lost Sea is America's largest underground lake and is located in Sweetwater, Tennessee. It is specifically located inside Craighead Caverns.
The Craighead Caverns are located in the foothills of the Great Smoky Mountains and at one time the caverns were owned by a Cherokee chief who used them as a meeting place for the Native Americans.
The Lost Sea was only discovered in the caverns in 1905. It was found by a young boy who wiggled himself through a narrow opening 300 feet underground and found a huge room that was partially filled with water. The room was so large that it swallowed his light before it even reached the walls or ceiling.
The Lost Sea is listed in the Guinness Book of World Records as America's largest underground lake. However, the lake remains a mystery. Although teams of divers have explored the lake, they have not been able to determine the full extent of the length and width of the lake. There has not been much scientific exploration of the cave.
The Lost Sea is now a tourist attraction. It is also a Registered National Landmark.
The Lost Sea Adventure provides a guided tour of the caverns. Tourists do advise that it is a long walk to see the lake but there is a boat ride. No diving or swimming is allowed in the cave.