Destination List > Mammoth Cave National Park
Mammoth Cave National Park
Photo by James St. John
Mammoth Cave National Park is in west-central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world.
In 1972, Mammoth Cave was unified with the even-longer system under Flint Ridge to the north to become the Mammoth–Flint Ridge Cave System. The park was established as a national park on July 1, 1941, 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.
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. Mammoth Cave is the world's longest known cave system with more than 420 miles (680 km) of surveyed passageways, which is nearly twice as long as the second-longest cave system, Mexico's Sac Actun underwater cave.