"Mammoth Cave National Park is a national park in south-central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. The park's 52,830 acres (21,380 ha) are located primarily in Edmonson County, with small areas extending eastward into Hart and Barren counties. The Green River runs through the park, with a tributary called the Nolin River feeding into the Green just inside the park.

"The cave system has formally been known as the Mammoth–Flint Ridge Cave System since 1972, when a connection was discovered between Mammoth Cave and the even-longer system under Flint Ridge to the north.[3] As of 2022, more than 426 miles (686 km) of passageways had been surveyed, over 1.5 times longer than the second-longest cave system, Mexico's Sac Actun underwater cave.

"The park was established as a national park on July 1, 1941, after oft-contentious eminent-domain proceedings whose consequences still affect the region. It was named a World Heritage Site on October 27, 1981; an international Biosphere Reserve on September 26, 1990; and an International Dark Sky Park on October 28, 2021." (Wikipedia)

"Mammoth Cave in Kentucky is the world's longest known cave system, with more than 400 miles explored, and one of the oldest tour attractions in North America," the National Park Foundation says.

"Mammoth Cave National Park preserves the cave system, a part of the Green River Valley, and the rolling hills of south central Kentucky. While cave tours of the 10 miles available in the cave are the park's big attraction, there is plenty more to do and explore while visiting this beautiful wilderness area, such as hiking, camping, horseback riding, fishing and kayaking.

"In 1926, a group of private citizens formed Mammoth Cave National Park Association to protect the park. Mammoth Cave National Park was officially dedicated as a national park by 1941.Mammoth Cave National Park was officially dedicated at as a national park by 1941. It then became a World Heritage Site in 1981 and an International Biosphere Reserve in 1990."

"Mammoth Cave National Park is more than just the home to the longest cave system in the world. It is a place for hiking, biking, horseback riding, canoeing, and camping on over 52,000 acres in south central Kentucky. Get inspired to plan your next vacation to Mammoth Cave National Park," the National Park Service says.

"Rolling hills, deep river valleys, and the world's longest known cave system. Mammoth Cave National Park is home to thousands of years of human history and a rich diversity of plant and animal life, earning it the title of UNESCO World Heritage Site and International Biosphere Reserve.

"A journey into Mammoth Cave on a guided cave tour is an essential part of a visit to the park. Whether it is your first time to the park or your tenth, there are several things to consider when planning your trip."

"The idea of another world existing beneath our feet is both thrilling and terrifying — and it’s the reality at Mammoth Cave National Park, which has the longest known cave system in the world. The park’s namesake cave runs more than 400 miles under the earth's surface — and that’s just the part that has been explored and mapped. Inside the aptly named Mammoth Cave, you’ll find tube-like passageways, great rooms with sparkling walls, slot canyons, huge domes, and even a dripstone that resembles a frozen waterfall," the Travel + Leisure says. 

"It’s no wonder Mammoth Cave has long drawn visitors to south-central Kentucky. And while it's easily the park’s biggest draw, it isn’t its only attraction. Mammoth Cave National Park is home to thousands of years of human history and stretches nearly 53,000 acres above the earth's surface. The landscape — rolling hills, thick forests, and lush river valleys — lends itself to hiking and biking, and the park is also traversed by the Green and Nolin rivers, which offer plenty of opportunities for boating and fishing.

"If you're interested in visiting a lesser-known park with lots to offer — it's also a UNESCO World Heritage Site and an International Biosphere Reserve — let us guide you through the wonders of Mammoth Cave National Park, including what to do, where to stay, and when to go."

"Like many places, Mammoth Cave—Kentucky’s only national park and the world’s longest cave system—saw its visitation hit hard by the COVID-19 pandemic," the National Geographic says.

"In 2019, more than half a million tourists descended on the 53,000-acre park, but that number fell by half in 2020 to just 290,000. Coronavirus precautions were partly responsible. The park limited its typical roster of almost 20 cave tours to a single self-guided tour, and provided timed tickets to groups of no more than 32 people. (As current federal mandates require, all visitors and employees are masked within federal buildings and the cave system.)

"Much has changed since humans first discovered Mammoth Cave more than 4,000 years ago. The ancestors of seven tribes associated with historic use of the parklands—including the Cherokee Nation and Shawnee Tribe—once used the cave system to mine minerals like gypsum with mussel shell scrapers harvested from the Green River. They told their own stories in petroglyphs, pictographs, and burials, leaving behind mummified remains."

"The world's longest known cave system just set a new record after surveyors spent hours mapping an additional 8 miles (13 kilometers) of the passageways at Mammoth Cave National Park in Kentucky," the Live Science says.

"The corridors at Mammoth Cave now measure a whopping 420 miles (676 km) in length, according to the National Park Service (NPS). That's about the distance between New York City and Raleigh, North Carolina.

"Mapping the cave system was a huge undertaking, carried out by volunteers at the Cave Research Foundation (CRF), a Kentucky-based nonprofit group, and other locals, including those from the Central Kentucky Karst Coalition."

"Mammoth Cave National Park is a designated UNESCO World Heritage Site as well as an International Biosphere Reserve located in central Kentucky. The park was established on July 1, 1941 and encompasses 52,830 acres of wilderness," the United States Geological Survey says.

"Mammoth Cave National Park is known for housing the world’s longest cave system, with over 405 miles (651 km) mapped. The vast cavern system was formed by water slowly dissolving Mississippian-aged carbonate rocks, creating sinkholes, tunnels, and underground rivers. This national park is also host to a diverse group of animal and plant species due to the microclimates created by varying light and temperature conditions.

"Mammoth Cave National Park has one the most famous karst topographies in the entire world. Karst terrain is created by dissolution of soluble rocks like limestone or dolomite and is characterized by the presence of cave systems, sinkholes, springs, and disappearing streams (surface water that suddenly flows underground). The park is located within the Central Kentucky Karst, a limestone belt that extends from southern Indiana through Kentucky into Tennessee. It is part of the Chester Upland and the Pennyroyal Plateau and is dissected by the Green River, which controls the cave development."

"Mammoth Cave near Cave City, Kentucky, is the world's longest cave. More than 367 miles (591 km) of passages have been mapped. To get an idea of how long Mammoth Cave is, you should consider that the second longest cave in the world, Optimisticeskay Cave, in the Ukrainskaya region of the C.I.S. (former Soviet Union), is only 143 miles (230 km) long. Mammoth Cave is three times longer than its nearest competitor. Not only is the cave the longest in the world, but cave mappers believe the cave system will eventually prove to be 560 miles (900 km) long!" the University of Kentucky says.

"Mammoth Cave was formed in Mississippian-age limestone rock. The cave is 379 feet (118 m) deep, and contains at least 5 levels of passages. The levels were formed in response to changes in the Ohio River during the late Tertiary and Quaternary Periods. The lower levels of the cave are still active and subject to back flooding from the Green River. If you visit the park, tours are available on lighted paths and, for the more adventurous, a wild cave tour is available on a reservation basis. To find out more about the park, visit the Mammoth Cave Web site.

"For all its magnitude, it should be remembered that Mammoth Cave is only one of many large caves in Kentucky. Kentucky is home to another 14 of the longest caves in the world. Prior to 1983, it was 3, but the 50 mile (80 km) long Roppel Cave System was connected to Mammoth Cave and removed from the list. The Fisher Ridge cave system currently ranks seventh on the world list, with a total length of 112 miles (180 km). Twelve other Kentucky caves are on the World's list of longest caves. A cave must have a minimum length of 15 km to be included on this list. To learn more about Kentucky caves, visit the list of caving organizations in Kentucky affiliated with the National Speoleological Society, or the National Speoleological Society website."

"The world's longest cave, protected as Mammoth Cave National Park in Kentucky, is longer than you might have thought. Recent efforts by the Cave Research Foundation have mapped eight more miles for the cave, bringing its currently accepted length to 420 miles," the National Park Traveler says.

"Mammoth Cave received its official designation as the world's longest cave system in 1969 with 65 miles of surveyed passageways. The connection between the Mammoth Cave system and the Flint Ridge system was discovered on September 9, 1972, by CRF cavers who traveled underground for more than 14 hours. This connection would bring the total mileage of the Mammoth Cave system to 144 miles.

"Volunteer organizations, like the Cave Research Foundation, provided Mammoth Cave with hundreds of hours of volunteer assistance in 2020. A variety of opportunities to volunteer for the National Park Service exist. While some volunteer positions require certain skills or abilities, others require no specialized training."

"Mammoth Cave National Park, located in the state of Kentucky, has the world's largest network of natural caves and underground passageways, which are characteristic examples of limestone formations. The park and its underground network of more than 560 surveyed km of passageways are home to a varied flora and fauna, including a number of endangered species," the UNESCO Heritage Center says.

"Mammoth Cave is the most extensive cave system in the world, with over 285 miles (458 km) of surveyed cave passageways within the property (and at least another 80 miles [128 km] outside the property). The park illustrates a number of stages of the Earth's evolutionary history and contains ongoing geological processes and unique wildlife.

"It is renowned for its size and vast network of extremely large horizontal passages and vertical shafts. Nearly every type of cave formation is known within the site, the product of karst topography. The flora and fauna of Mammoth Cave is the richest cave-dwelling wildlife known, with more than 130 species within the cave system."

"This is the longest-known cave system on earth, but there are breathtaking sights and amazing adventures to be found above ground, too," the Kentucky Tourism says.

"More than 400 miles of vast chambers and winding rock tunnels of Mammoth Cave National Park have been explored so far, and countless more remain untouched. Descend into the earth and discover the rare beauty and mystery of the cave for yourself on a guided tour, ranging from 30 minutes to five hours. Above ground, nature lovers will enjoy hiking, horseback riding, ziplining and rock climbing, plus canoeing and kayaking on the Green and Nolin rivers, which flow right through the park.

"Nearby Cave City, a certified Kentucky Trail Town, is a great place to make your home base for adventure. Here you can explore more caves, take a spin in a go-kart, play a round of miniature golf, or go back in time to when dinosaurs roamed the earth at Dinosaur World and other adventure parks. Spend the night under the stars at a cozy cottage, B&B or campsite. And be sure to bring home a treasure to remember your trip by, from rocks and minerals to locally made quilts and crafts."

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