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Located in Sweetwater, Tennessee, just a little over an hour northeast of Chattanooga, is the Lost Sea Adventure. This historic cavern contains the largest underground lake in America. 

When you visit the Lost Sea Adventure, you get to take a tour of the cavern’s rare formations and take a boat ride on the underground lake.

Craighead Caverns

The Lost Sea Adventure is located in a historic cave system known as Craighead Caverns. Your tour of the caves begins with a descent down a bright yellow tunnel into the vast first room of the caverns. These caverns are large and wide open with unique and rare rock formations at every turn.

The caves have been used and explored for many years. The Cherokees used them as a meeting place. Later, Confederate soldiers mined the caves for saltpeter to use in gunpowder. In 1939-1940, mushroom farmers used the cool temperatures to grow their crops. Then, in 1947, the large room was turned into the Cavern Tavern nightclub, and a wooden floor was installed; this didn’t last long, though, as patrons had a hard time getting drunk in the low altitude below ground, but the booze would hit them on their way up the steep steps, and they’d come tumbling back down!

Throughout your tour, you’ll learn about the interesting formations found in the cavern. These include the “Bear Paw” that visitors are allowed to rub for good luck and rare crystalline structures called “anthodites,” which are spiky clusters commonly referred to as “cave flowers”. These “cave flowers” are only found in a few caves around the world.

Lost Sea sweetwater Tennessee

The Lost Sea

Of course, the highlight of the tour is visiting the Lost Sea. Though there had been rumors of a large lake somewhere in the cave system, it wasn’t discovered until 1905. Ben Sands, a 13-year-old boy who often played in the caverns, found this large room half-covered with water.

The full extent of the Lost Sea is still unknown. The visible portion of this underground lake is 800 feet long by 220 feet wide. Divers have managed to discover a series of connected rooms even larger than this completely filled with water. They’ve mapped out more than 13 acres of water so far but still haven’t found the end of the lake. The Lost Sea Adventure team has even introduced rainbow trout to the lake in the hope of finding where the lake flows out, but so far, all the fish have stayed in the caves.

A tour of the Lost Sea takes you out on the lake in glass-bottomed boats. As you float on America’s largest underwater lake, you’ll learn more about the system of underwater lakes and the team’s attempts to find the end of the waters.

the lost sea adventure tn

the lost sea family adventure Tennessee

Touring The Lost Sea Adventure

The Lost Sea Adventure is located in Sweetwater, Tennessee, on Hwy 68, just seven miles off I-75, exit #60. 

The lake is situated 140 feet below the ground, so walking to and from the lake can be quite a hike. The tour of the caverns includes a ¾ mile walk, round trip. The temperature in the caves is always around 58°, so be sure to bring a light jacket and some walking shoes that you don’t mind getting dirty.

The Lost Sea Adventure is open every day except Thanksgiving and Christmas. Tours take about an hour and 15 minutes. Before and after the tour, you’ll be able to visit the small shops in the Lost Sea Village, take a walk on the surrounding Nature Trail, and browse the gift shop.

Admission to the Lost Sea Adventure costs $21.95 for adults, $12.95 for children, and free for children under 3. 

lost sea adventure

This article was written by Paige Watts of Paige Minds the Gap

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