The country’s largest underground lake is just 2 hours from Atlanta

The Lost Sea in Sweetwater, Tennessee, is part of the Craigshead Caverns

You can take a boat ride on this Tennessee lake and not have to worry about getting a sunburn.

The Lost Sea, America’s largest underground lake and a registered national landmark, is about two hours up Interstate 75 in Sweetwater.

It is part of an extensive cave system called Craighead Caverns and was pretty much unknown until 1905, when “a 13-year-old boy named Ben Sands wiggled through the tiny, muddy opening 300 feet underground and found himself in a huge room half filled with water,” its website states.

A visit to the Lost Sea begins with a guided tour of the caverns, which are about 58 degrees all year.

During the tour, guides will tell you of the caverns’ history, including how it was once used by the Cherokee Indians and how Confederate soldiers mined it for saltpeter to make gun powder.

At the bottom of the cave, you’ll board a glass-bottomed boat to explore the lake, which covers more than four acres. Although the visible part of the lake is 800 feet long by 220 feet wide, its full extent is still not known.

According to the website, one of the cave’s earliest visitors was a giant Pleistocene jaguar whose tracks have been found deep inside the cave.

About 20,000 years ago the animal apparently lost its way and fell into a crevice. Some of its bones, discovered in 1939, are on display in the American Museum of Natural History in New York. Others, along with plaster casts of the tracks, are among the exhibits at the visitor center.

In addition to the caves and lake, you can explore the Lost Sea Nature Trail, and visit the general store, ice cream parlor, gem mine and glassblower

Lost Sea

140 Lost Sea Road, Sweetwater, TN 37874

Tickets cost $24.95 for adults and $14.95 for ages 4-12. Children 3 and younger are free.