18 May The Lost Sea Adventure: Underground Lake in Tennessee

Have you ever explored an underground lake before? Well, I had not before visiting the Lost Sea Adventure in Tennessee while on a road trip from Pennsylvania to California. I bought a daily tour ticket, which allowed me to explore the caverns as well as ride in a boat on the underground lake 140 feet (~43 meters) below the surface. To this day, researchers are still unsure of the size of the lake. It is so large they have thus not yet been able to map out all of it. Keep reading below to plan your own visit!

While Glacier National Park does not have any underground lakes (that I know of), it does have an array of stunning lakes. For example, Iceberg Lake is a beautiful blue color while Avalanche Lake has crystal clear waters.

Contents:

1) Lost Sea Adventure Location

2) Opening Hours and Entrance Fee

3) The Best Time to Visit

4) Quick Facts

5) Background

6) Additional Attractions

7) Tour Options

8) Recommended Items to Bring

1) Lost Sea Adventure Location

The Lost Sea Adventure is located in Sweetwater, Tennessee. It is just a two and a half hour drive west from Asheville, North Carolina. Moreover, it is only a 50 minutes drive southwest of Knoxville, Tennessee.

There are a lot of other attractions in the area worth visiting. For example, try to schedule time in your itinerary to Clingmans Dome at Great Smoky Mountains National Park and Fall Creek Falls State Park in Spencer, Tennessee.

Parking

There is a parking lot located right by the main building, so no need to worry about finding a spot for your visit. 

Nearby Lodging

For lodging, check out accommodations offered in the town of Sweetwater. Otherwise, you can stay in the city of Knoxville and make a day trip to the Lost Sea Adventure. 

Nearby Airports

There are a few nearby regional airports, with the main one being McGhee Tyson Airport in the city of Knoxville. It is 50 minutes northeast of the Lost Sea Adventure. The closest international airport is the Hartsfield-Jackson Atlanta International Airport, which is three hours south. 

Rock formations within the cave

2) Opening Hours and Entrance Fee

The Lost Sea Adventure is open (almost) every day of the year. It is only closed on Thanksgiving Day and Christmas Day. Its hours of operation differ slightly based on the time of year, but they are generally 9:00am to 5:00pm. They are then open a few extra hours in the evening in the summer months. Check out their website to confirm the hours for the day you plan to visit.

Entrance Fee

An adult ticket costs $25 while a child ticket costs $15 (for ages four to 12) for the daily tour. The daily tour allows you to walk around inside the caves as well as take a boat ride on the underground lake.

On the other hand, a daytime wild cave tour costs $37 per person while an overnight wild cave tour costs $47 per person. The wild cave tour allows you to walk, crawl, and explore the caverns to a greater extent than the daily tour. Additionally, you can choose to spend the night in the caves. 

Check out their website for more information on special pricing for groups and tours. Additionally, I have more information about the tour options in section seven below. 

3) The Best Time to Visit – Lost Sea Adventure

Ready for some good news? There is truly no bad time to visit the Lost Sea Adventure. They are open all year round, and thus you can visit in December or July. 

In terms of how much time you need to plan in your itinerary for the Lost Sea Adventure, that will differ based on the tour chosen. For example, plan between one hour and an hour and a half if you book the daily tour. On the other hand, plan for six hours if you book the daytime wild cave tour. If you book the overnight wild cave tour, you need to plan for around 15 hours. 

Getting ready to board a boat on the underground lake

4) Quick Facts

1. Lost Sea Adventure is located in Sweetwater, Tennessee. 

2. It is open all year round, generally from 9:00am to 5:00pm. 

3. The tour options include a daily tour, a daytime wild cave tour, and an overnight wild cave tour. 

4. Lost Sea Adventure includes an underground lake, which was discovered in 1905. 

5. The size of the underground lake is still unknown as divers continue to explore more of it with no end in sight. 

5) Background – Lost Sea Adventure

Visitors can enjoy the largest underground lake in the United States at the Lost Sea Adventure. How large is it, you might ask? Well, that is somewhat of a mystery. Researchers do know it is at least 220 feet (~67 meters) wide and 800 feet (~244 meters) long. However, the full extent of the lake has not yet been discovered. Every time divers try to map out more of the lake, they just keep finding more and more water with no end in sight.

First Visitors and Discoveries

The lake exists in the Craigshead Caverns system. One of the first known visitors to the cave was a jaguar over 20,000 years ago. Its bones are not on display in the caverns but instead at the American Museum of Natural History in New York. The next known visitors were the Cherokees. Multiple Cherokee artifacts were found in the caves, thus providing evidence of their presence. Then in the 1800s white settlers used the cave for food storage, and later the Confederate Army mined for gunpowder materials. 

Nevertheless, none of these people groups are believed to have found the underground lake. A child by the name of Ben Sands discovered the lake in 1905 when he was only 13 years old. After crawling, shimmying, and wiggling through the cavern system hundreds of feet, he found himself in a room partially filled with water. 

Just 10 years later in 1915 the public began to utilize the caves for activities such as dancing, cockfights, and producing moonshine. Visitors can now visit the caves to see its networks of caverns, crystalline structures, and underground lake. The crystalline structures are a rare variety known as “cave flowers”. These cave flowers are only found in a few caves throughout the entire world. 

Rock formations in the cave

6) Additional Attractions

There is so much more to see here than just the largest underground lake in the United States (though that might be the star attraction). During your visit, plan to also check out the café, sweet shop, and general store for a quick snack and souvenirs. Next, stop by the gem mines to find some gems of your own. Then visit the glassblower and stroll down the Lost Sea Nature Trail.

Some unique rock formations in the cave

7) Tour Options

There are two main tour options. First, the daily tour includes a walking tour and a boat ride. Second, the wild cave tour includes crawling through the caverns and an optional overnight portion.

Daily Tour – Lost Sea Adventure

• Approximate time: 1 hour 15 minutes
• 0.75 mile (~1.2 kilometer) loop walk + underground lake boat ride
• Price: $25 for adults | $15 for children (ages 4 – 12)

If you want a leisurely walk around the caves and a boat ride in the underground lake, then the daily tour is the one for you. First, the tour includes a 0.75 mile (~1.2 kilometer) walk around a loop in the caverns. Please do note that the pathway is steep in some places, so do be wary of this tour if you have trouble walking on steep inclines. Second, after finishing the loop you will head to the underground lake boat ramp. Enjoy a boat ride 140 feet (~43 meters) below the surface on the largest underground lake in the United States.

Wild Cave Tour – Lost Sea Adventure

• Daytime and overnight tour options
• 12 participant minimum for booking (with exceptions)
• Price: $37 for day tour | $47 for overnight tour

Tour Schedule

If you want to truly immerse yourself in the Craigshead Caverns system at Lost Sea Adventures, then book tickets for the wild cave tour. Round up everyone for the tour and be sure to arrive no later than 6:00pm the night the tour begins. While the tour will begin at 6:30pm, you still have to check in and be ready to go. Therefore, be sure to arrive at least 30 minutes in advance.

Then the fun begins! You will walk, crawl, and everything in between during the tour until settling down for the night at 11:00pm. That is right – you sleep in the cave overnight. There is not more of a “wild cave tour” than that! Wake up the next morning around 7:00am so the group can clean up all of their personal belongings and then head out by 8:00am.

If you do not want to sleep overnight in the cave, there is a day option for the wild cave tour.

Group Size for Booking

Please note you generally cannot book this tour as an individual. The minimum number of participants for booking is 12. To book the tour for less than 12 people, you will have to pay the full amount for 12 participants and ensure there is at least one adult chaperone. Why these rules, you might ask? The tour is designed specifically for tour groups, such as church youth groups, school field trips, etc. 

What to Bring / Wear

As mentioned above, this is a wild cave tour. You will not be admitted to participate if you are wearing shorts. What should you wear? I will list out items briefly here as well as in the next section. It is recommended to wear long pants, a light jacket, and close-toed shoes. Additionally, bring a change of clothes to sleep in as your other clothes will get dirty throughout the tour. The cave stays at an approximate 58 degrees Fahrenheit (~14 Celsius), so plan accordingly.

For sleeping purposes, bring a sleeping bag or something similar to put on the ground to stay comfy and cozy all night long. There are no showers in the cave, though thankfully there are toilets. Bring wet wipes, dry shampoo, or other similar items to keep clean. Additionally, pack any medications or other necessary items. However, do not overpack. It would not be enjoyable to carry a large backpack through the caves.

The underground lake at Lost Sea Adventure

8) Recommended Items to Bring – Lost Sea Adventure

For general packing recommendations for road trips, check out my summer road trip packing list as well as my list of travel essentials for pop up campers.

1. Water bottle: Be sure to bring water with you while visiting the Lost Sea Adventure as there is no water available. Water is even more important if you book the wild cave tour, for you will be in the caverns for a longer period of time and also will be more active overall. For example, I always carry around my Yeti water bottle.

2. Flashlight: The flashlight will help you see all the beauty and wonders of the cave, especially during the wild cave tour. A unique type of headlight would be this one embedded within a beanie.

Apparel 

3. Light jacket: The caverns stay at a crisp 58 degrees Fahrenheit (~14 Celsius), so you will want a light jacket to help keep you warm.

4. Hiking shoes: A pair of hiking shoes will come in handy on the daily tour and especially on the wild cave tour. If you plan to do the wild cave tour, you will need to wear close-toed shoes even if they are not hiking shoes. 

For the Wild Cave Tour Specifically

5. Long pants: You will be crawling and maneuvering around the caverns on the wild cave tour, so you will want to protect your knees and legs from getting all scraped up. 

6. Extra set of clothes: You are likely to get fairly dirty and muddy during the wild cave tour. Therefore, bring an extra set of clothes so that you can change into something clean once the tour is complete. 

7. Medication: If you book the overnight wild cave tour, be sure to bring along any medication you will need to take before you go to sleep. 

8. Sleeping bag: Pack a sleeping bag or mat if you book the overnight wild cave tour. Otherwise, prepare to sleep on the cold, hard ground. 

9. Other overnight essentials: Pack anything else you might need. For example, dry shampoo, lotion, etc. However, be sure not to overpack as it is only one night. 

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Check out articles on some of my other cross-country road trip stops:

New River Gorge Bridge Lookout in West Virginia

Lost World Caverns Tours in West Virginia

Road to Nowhere Tunnel in Bryson City, NC

Falls of Hills Creek Waterfall Trail in West Virginia