15 Eerie Caves in the U.S. You Can Actually Visit
Check your fear of the dark at the door.
For outdoor enthusiasts, it can sometimes feel like everything’s been done—every trail has been hiked, every mountain has been summited, and suddenly, you’re considering taking up an indoor hobby like knitting. But wait! Instead of ascending peaks, now may be the time to consider descending below the surface.
There are an estimated 45,000 caves and caverns in the contiguous US alone—including the longest cave system on earth—meaning there’s really no limit to the number of underground passageways available for you to enjoy, from lava tubes to dive sites, replete with stalagmites and stalactites. Just make sure you’ve conquered your claustrophobia and any lingering fear of the dark. We've picked out some of the best caves in the US, all ripe for exploration, many of which offer family-friendly excursions, as well as expeditions led by tour guides.
Mammoth Cave National Park, Kentucky
This UNESCO World Heritage Site is the longest cave system in the world with 400 miles of explored caves. Both guided and self-guided tours are available year-round, with scenic routes ranging in difficulty from relatively easy to ultra-challenging. The multitude of guided tours highlights some of the cave’s most iconic features: The Historic Tour visits the historic areas that originally made Mammoth Cave famous, while the Gothic Avenue Tour, fit for architecture nerds, takes you through rock formations resembling Gothic architecture. Bonus: If you happen to visit when it's storming outside, you may even see a layer of fog form inside the cave. Very eerie.
Williston, Florida
Some caves feature underwater rivers, lakes, or waterfalls, but Devil’s Den Spring is a full-on dive site. It was formed by a karst window—essentially, a cave roof that collapses, revealing a prehistoric underground river. (The result looks similar to a cenote.) Divers can view ancient stalactites and fossil beds dating back 33 million years through the crystal-clear, brilliantly blue water, which reaches maximum depths of 54 feet and maintains a steady temperature of 72 degrees year-round.
Sullivan, Missouri
With more than 6,400 recorded caves—though only 20 are open to the public for guided tours—Missouri is known as the "Cave State." Meramec Caverns is the largest and most well-known system of the bunch, thanks to its location along historic Route 66, its notoriety as a former hideout for outlaw Jesse James and his gang, and its heralded past as a stop along the Underground Railroad. These days, it's outfitted with neon signs, multicolored mood lighting, and manmade props along well-lit guided tour routes. Meramec's 150,000 annual visitors can expect to see an ancient limestone Wine Table (which they call the "world's rarest cave structure") and a seven-story "mansion" built underground.
Custer, South Dakota
There are so many cool things to see above ground in the Black Hills of South Dakota—you’d never expect there to be just as many cool things to see beneath the surface. But Jewel Cave, which was designated a national monument in 1908, has more than 180 miles of mapped and surveyed passageways, making it the third-longest cave system in the world. The cave delivers on its name, with large calcite crystals covering the walls and ceilings that look like dripping jewels. (There’s also a 10-foot-long piece of flowstone called “cave bacon.") You can take one of three different guided tours through the caverns ranging in difficulty from easy to strenuous.
Hot Springs, South Dakota
The world’s first-ever cave to be designated a national park, Wind Cave (so named for the whistling wind ever-present at its entrance) is one of the longest and most complex systems on earth. Home to 95 percent of the world's boxwork—delicate, web-like cave formation that remains one of the park’s many mysteries—visitors can explore Wind Cave through ranger-led tours. Check out the magnificent wildlife that surrounds the caverns, including bison, elk, and prairie dogs, before delving underground for even more natural wonders.
Luray, Virginia
Some 400 million years in the making, the Luray Caverns in Virginia's Shenandoah Valley are the largest, most popular caverns in the eastern US. Each year, half a million visitors come to see the system’s dramatic underground rock formations, with guided tours that take you through Giant’s Hall (billed as "Geology's Hall of Fame") with its towering Double Column, Frozen Fountain, Dream Lake, Saracen’s Tent, and Titania's Veil. Here, you'll also find the Great Stalacpipe Organ—the largest musical instrument in the world, which uses electronically controlled rubber mallets to gently tap the cave's stalactites, turning three acres of the cave into a music hall.
Carlsbad Caverns National Park, New Mexico
If you’re worried about overheating in New Mexico’s Chihuahuan Desert, rest assured: Things cool down quick inside the 250-million-year-old limestone caves that make up Carlsbad Caverns National Park, which you can explore on a self-guided tour or a ranger-led tour for an additional fee. The 357,480-square-foot Big Room—the largest single cave chamber in the US—is the most popular cave, drawing some 300,000 visitors each year. Other areas, like the Hall of the White Giant and the Spider Cave, require crawling. If you're visiting between May and October, stick around for the Bat Flight Program, when hundreds of thousands of Brazilian free-tailed bats exit the cave at dusk to forage for food.
Sweetwater, Tennessee
Inside Craighead Caverns, you'll find the largest non-subglacial underground lake in the United States (and the second-largest in the world!), known as the Lost Sea. On the Lost Sea Adventure, visitors can explore during the day or choose to spend the night deep underground as they venture through undeveloped cave rooms and squeeze their way through some very tight spaces. The cave also features an underground waterfall and anthodites (aka "cave flowers"), a unique geologic structure so rare, the Lost Sea contains 50 percent of the world's known formations.
Benson, Arizona
Kartchner Caverns is a 2.4-mile system of underground passageways located in southeastern Arizona. Visitors to Kartchner Caves can choose from several different guided tours, where they may spot the 58-foot Kubla Khan, the largest underground column formation in Arizona; the world’s longest soda straw stalactites; or the 1.2-acre Big Room, which is home to the world's most extensive formation of brushite moonmilk, a milky white cave deposit. Note that the Big Room is closed each summer, as it is a nursery roost for more than 1,000 cave bats.
Howes Cave, New York
Located in the tiny hamlet of Howes Cave in upstate New York, Howe Caverns and neighboring Secret Caverns both offer tours of underground wonderlands with stunning water features… but that’s just about where the similarities end. Howe Caverns features a boat ride along the calm, glassy surface of an underground lake, while Secret Caverns has a thunderous 100-foot underground waterfall. Howe Caverns offers a more structured experience, while the vibe of Secret Caverns answers the question, “What if your woo-woo aunt who’s lived in an artist commune since the '70s decided to buy a cave and make it a tourist attraction?” Whichever you choose will be extremely worth your time and money, and since they’re right next to each other, we recommend hitting both.
San Antonio, Texas
As the old adage goes, everything is bigger in Texas. Naturally, that includes the Natural Bridge Caverns, the largest commercial caverns in the country. Named for the 60-foot natural limestone bridge near its entrance, Natural Bridge offers a few different kinds of tours, one of which—the Adventure Tour—will have you crawling through narrow passageways to see undeveloped cavern rooms. (Yes, you will be covered in mud, and it's a glorious experience.) This is also the home of the world’s largest bat colony, which visitors can witness during the summer months when millions of free-tailed bats come whizzing out of the cave at dusk for their nightly food foraging.
Chattanooga, Tennessee
Lookout Mountain is home to some extremely popular Chattanooga attractions, including zip lines and a century-old limestone castle—but there’s no denying that the main draw is 145-foot Ruby Falls. You’ll descend 260 feet underground in a glass-front elevator and spot ancient formations along the cavern trail before laying your eyes on the thundering falls, lit up by color-changing spotlights. On special after-hours tours, you can also try a descent illuminated only by handheld lanterns.
Gifford Pinchot National Forest, Washington
Formed 2,000 years ago when Mount St. Helens erupted, the Ape Caves are the longest continuous lava tube in the continental US, stretching along beneath the earth for more than two miles. The cave is open all year—but keep in mind that the temperature inside tends to sit at 42 degrees same-day year-round, and the walls are slick with water and "cave slime." The Upper Cave is more rugged and challenging, with a slick eight-foot lava fall you’ll need to scale and some tight spaces to squeeze through. The Lower Cave—a broad tube with a flat floor that descends gently—is much easier to navigate. While making your way through the latter, keep an eye out for the formation called The Meatball, a blob of lava rock that fell from the ceiling as the tube was forming and petrified, creating a rather intimidating archway.
Vallecito, California
Moaning Cavern is home to the largest public cave chamber in the state of California, a cavern tall enough to fit the Statue of Liberty from toes to torch. Visitors will descend 65 feet underground to check it out (and cardio champs can head further down the century-old, 100-foot spiral staircase to stand at the base). This is also home to some of the oldest human remains ever discovered in America: 13,000-year-old bodies belonging to prehistoric people who, whoops, likely slipped and fell into the cave's opening. Allegedly, the moaning sounds for which the cave is named are caused by water dripping into holes on the cavern floor… but history considered, we’re gonna guess the sounds are actually ghosts.
Pigeon Mountain, Georgia
Guided tours a little too soft for you? Located inside Ellison's Cave—a pit cave found on Pigeon Mountain in northwest Georgia—the Fantastic Pit is everything your hardcore heart desires. Grab your helmet, your harness, and your “critter,” and get ready for the deepest free-fall pit in the Lower 48 at 586 feet deep. The Fantastic Pit is big enough to hold the Washington Monument (555 feet tall) and is nearly twice the height of the Statue of Liberty (305 feet tall). This cave system is only for seriously experienced cavers; there have been several fatalities here, most due to hypothermia from getting stuck in the cold, wet environment, so proceed with caution.