The "Lost Sea" can be found 140 feet beneath the Tennessee mountains near Chattanooga! The largest underground lake in the country...here you can take a glass-bottom boat ride across the clear waters while massive rainbow trout swim below and ancient caverns rise around you. The experience begins with a walk through a unique tunnel, followed by a guided tour through the cave’s chambers. At the bottom, you’ll board your boat and float across the hidden lake as your guide shares the cave’s rich history, including its use by Cherokee Indians and Confederate soldiers. Tours last about 75 minutes, and the constant 58-degree temperature makes it a fascinating year-round destination.