Did you know that the South is home to the world’s longest cave system and the largest underground lake in the United States? Or that there are numerous caves where you can also enjoy dining, entertainment and history? The region has all this and more, at some of the most unique cave locations to visit during the summer. Check out these favorites: --- Lost Sea in Tennessee America’s largest underground lake is part of the Craighead Caverns cave system in Sweetwater, Tennessee. You can tak...