Squirreled away in the American South within a two-hour radius of famous cities like Louisville, Lexington, and Nashville lies a vast network of tunnels and passageways that together form the longest cave system in the entire world. Home to over 130 species of wildlife and almost every type of cave formation, it’s also the world’s most diverse series of caverns. You may have heard of it: Kentucky’s aptly-named Mammoth Cave National Park. Let’s take a journey inside this stunning natural wonder.

Welcome to the rolling hills of west-central Kentucky, nestled on the edge of America's Southern Appalachian Region.
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It's a beautiful, fascinating area; ancient in its history and rugged in its topography... and there's more to it than meets the eye. Much more.
Hidden away deep beneath these stunning slopes lies a national treasure: Mammoth Cave.
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By far the longest cave system in the world, this sandstone labyrinth encompasses more than 400 miles of known passageways, with more being discovered each year.
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Not only is Mammoth Cave a national treasure, acknowledged by its designation as a National Park, but it's also been recognized internationally as the longest, most biologically diverse cave system in the world. As such, Mammoth Cave has been named a United Nations Educational, Scientific, and Cultural Organization World Heritage Site and Biosphere Reserve.
These designations help protect and preserve the rich geologic and biologic diversity housed within Mammoth Cave for generations to come.
National Park Service
A trip to this one-of-a-kind natural wonder should begin here, at the most famous entrance to Mammoth Cave - the iconic arched entry hidden behind a thin, shimmering waterfall veil.
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There are other entrances to this truly massive cave system, however, this one is certainly the most dramatic.
Behind the veil, a stunning underground world awaits.
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Once inside, the incredible sights are almost endless.
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Tours led by rangers at Mammoth Cave National Park range from short, well-marked routes to extensive off-trail forays into the wild bowels of this vast network of passages.
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Popular tour options include guided walks past stunning features like Frozen Niagara, Grand Avenue, Fat Man's Misery, and The Rotunda.
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You'll be awestruck by the diversity of delicate formations around every corner.
This formation, known as The Frozen Niagara, is one of the most famous and was discovered in the early 1920s.
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Its name comes from its resemblance to Niagara Falls when it freezes over in the wintertime.
While Mammoth Cave is most famous for being the longest known cavern system, the impressive height of areas like Mammoth Dome is mind-blowing.
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And it's not just the geology of the cave that people flock to see; it's also filled with history.
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Three millennia ago, the cave was used by prehistoric people as a mineral mine. Evidence of this ancient activity can be found in the form of thousands of perfectly-preserved artifacts still littering the cave's passageways. Mammoth Cave also seems to have been used as an ancient burial site, as the relatively recent discovery of carefully buried, naturally mummified human remains suggests.

Ever since, for good or for ill, the cave has continued to provide shelter, materials, jobs, and recreational opportunities for a variety of groups in a wide range of historical time periods, including our own.
There's plenty to do above ground at Mammoth Cave National Park as well.
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Hiking trails wind through fairytale forests and past abandoned cemeteries, historic buildings, and panoramic overlooks. Campsites perch on the banks of the Green River, allowing the peaceful sound of the rushing water to lull you to sleep after a full day of adventuring. Spacious, accessible visitor centers provide a wealth of information and a range of ways to experience the history and beauty of this unique area.
There's no doubt about it, this remarkable cave, the only of its kind the world over, definitely merits a spot on your travel bucket list.
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To learn more about Mammoth Cave National Park and plan your visit, see the park’s website here.

General Information:

Accessibility: Mammoth Cave National Park offers fully accessible trails, visitor centers, campgrounds, shops, and lodging, though certain deep-cave tours are not suitable for those with limited mobility. The Accessibility Tour is the best choice for visitors with mobility devices, motorized wheelchairs, and walkers. Audio and visual aids are available for all levels of low vision and hearing loss needs. For more information about park accessibility, click here.

Pet Friendly: Pets are permitted on the trails of Mammoth Cave National Park on leashes of a maximum of six feet length, but they are prohibited in the park buildings and in Mammoth Cave itself. Pets may be boarded on-site at Mammoth Cave Kennels.

Parking: Parking is free, plentiful, and well-marked throughout the park.

Seasonal Access: The park is open year-round, with the exception of certain government holidays.

Cost: Entry into Mammoth Cave National Park is free. Cave tour prices range from $4 per person (Discovery Tour, Senior, or Access Pass holder) to $66 per person (Adult Wild Cave Tour). Campground and picnic shelter reservation charges also apply.

Other: Cave temperature can vary widely, especially near the entrances and during the winter, but deeper portions of the cave remain at a constant 54 degrees, even during the hottest months of summer. A light jacket is recommended, no matter when you visit.

Feeling inspired to fill your Bucket List? Check out our previous features of Hoh Rain Forest in Washington, Going-to-the-Sun Road in Montana, and the beautiful Florida Keys, then subscribe to our weekly Bucket List newsletter to discover new destinations across the country that definitely deserve a visit.

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Mammoth Cave, KY 42259, USA