Lights in The Lost Sea cavern

Take A Glass-Bottomed Boat To Explore The US' Largest Underground Lake

By Dawn Hammon


The Lost Sea in Sweetwater, Tennessee, is the largest underground lake in America and offers a one-of-a-kind opportunity to explore an underground world of water.
The Lost Sea is a cavern system that leads to a massive lake 140 feet below ground. Visitors will pass through tunnels and rooms while guides explain the history of the location.
Rare anthodites or "cave flowers" are hidden in the caverns. The Lost Sea has a deep history, as it was likely a Cherokee gathering place and used by settlers to store food.
The caves maintain a steady temperature of 58 degrees year-round. Visitors are loaded into an electric boat that carries them on a tour of the exposed surface of the lake.
The water is around 75 feet deep and expands over 4.5 acres. Looking into the water, you'll likely catch a glimpse of the many huge stocked rainbow trout in the water.