Explore Craighead Caverns and The Lost Sea — America’s Largest Underground Lake

Complex cavern systems located deep below the earth’s surface and lined with exquisite crystal formations are just the start of what makes these caverns worth a cave dive. Add a large and beautiful underground lake to their otherworldly appeal, and you have a recipe for an unparalleled travel experience. This fascinating and rare combination of subterranean features is precisely what Craighead Caverns in Sweetwater, Tennessee offers — and visitors can explore the intricate caverns on foot and the lake by boat with a guided tour by The Lost Sea Adventure.

Why Visit the Craighead Caverns

Keel Room at Craighead Cavern.
Keel Room at Craighead Cavern. Photo credit: Owen Smith.

Sweetwater, Tennessee, located in the foothills of the Great Smoky Mountains on the eastern side of the state about 46 miles southeast of Knoxville, welcomes visitors with a revitalized historic downtown and main street lined with charming shops and eateries. But the area’s major highlight is the sprawling Craighead Caverns, named after a former owner, Chief Craighead, a Native American Cherokee who acquired the land through the Ocoee or Hiwassee Land Grants.  Located 140 feet below ground, they’re famous for the enormous lake they house, The Lost Sea — the country’s largest underground lake and the second largest one in the world.

The caverns have a gripping story to tell. Even if this natural wonder didn’t boast incredible beauty, its storied past would be reason enough to visit. Cherokee councils used the caverns as their meeting place in the 1820s (the caverns are located just 25 miles from Chotow, the historic capital of the Cherokee nation, where the community of Vonore now sits). Around the same time, the first white settlers in the Tennessee Valley used the naturally chilly underground space (it’s a constant 58 degrees) to store potatoes and other vegetables.

Confederate soldiers mined the caverns for saltpeter and used it to manufacture gunpowder during the Civil War in the 1860s (a date torched on the walls bears testament to the enterprise). Moonshiners operated stills in the caverns during the Prohibition era to evade the law and a mushroom farm also operated in them from 1939 to 1940. Around the same time, explorers discovered the fossil and tracks of a gigantic Pleistocene jaguar that died in the caverns about 20,000 years ago. You can now see some of the creator’s bones at New York’s American Museum of Natural History.

Rock Formations and Waters That Wow

It’s easy to see why this marvel needs to be seen and safeguarded. Starting from a small opening on the side of the mountain, visitors can tour the caverns — a series of enormous “rooms” that open out to one another. One of these cavern spaces, now called “The Council Room,” contains artifacts including pottery, arrowheads and jewelry from the Cherokee.  

The mineral and rock formations run a gorgeous gamut, from hanging white streaks known as drapery or cave bacon (the result of water leaching iron out of the rock) to rare clusters of spiked crystals called anthodites or cave flowers. The Lost Sea contains half of the world’s known anthodite formations.

A Deep Dive Into the Lost Sea

The visible portion of the lake covers 4.5 acres and it is at least 70 feet deep, but its full size is still unknown despite the many diving expeditions that have taken place to assess it. Using state-of-the-art diving equipment, divers have discovered additional water-filled rooms and mapped 13 acres of water, but no definite end to the lake has been determined.

A Tour That Lets You Experience This Epic Destination

Waterfall in Craighead Caverns in Sweetwater, Tennessee.
Waterfall in Craighead Caverns in Sweetwater, Tennessee. Photo credit: Owen Smith.
The Lost Sea at Craighead Caverns in Sweetwater, Tennessee. .
The Lost Sea at Craighead Caverns in Sweetwater, Tennessee. Photo credit: Lost Sea Adventures.

The 1.5-hour guided Lost Sea Adventure tour lets you experience the caverns and The Lost Sea in all their glory. On it, you’ll enter the caverns via a long, narrow yellow tunnel, then walk along sloping pathways that trace its various “rooms.” During the journey, you’ll learn about the awe-inspiring history and geology of the immense cavern spaces. At the bottom, you’ll board a glass-bottomed electric boat that will ferry you around The Lost Sea.

As you cruise along the lake by boat, you can size up its cold 56-degree temperature by quickly dipping your fingers into the water. You’ll also spot rainbow trout — about 300 populate the lake and, given the extreme clarity of the water, you’ll see them swim by.

Check out the tour company’s site for pricing and ticket information.

Other Things to Do in the Sweetwater Area

While you’re in Sweetwater, take some time to explore other man-made and natural attractions in the area.

Visit Tasali Notch Vineyard, 6 miles south of Craighead Caverns. The vineyard offers up beautiful views of the Cherokee National Forest and Great Smoky Mountains. Sample wines made from muscadine grapes, a variety indigenous to the southeast. Tasali Notch is Tennessee’s largest muscadine vineyard. Private tours and tastings are available by appointment.

Starting in Tellico Plains, Tennessee, 23 miles south of Craighead Caverns, travel the beautiful 43-mile-long Cherohala Skyway, a National Scenic Byway that crosses through the Cherokee National Forest in Tennessee and the Nantahala National Forest in North Carolina, the largest of the state’s four National Forests. You’ll see forest-covered mountains and panoramic views from multiple scenic overlooks.

Smoky Mountain National Park.
Smoky Mountain National Park.

Read next: Road Trip Stops in the Great Smoky Mountains and Blue Ridge Parkway. “Scenic” doesn’t even begin to describe the views along this mountain-filled journey.