|Mammoth Cave National Park|
|Location||Edmonson, Hart, and Barren counties, Kentucky, U.S.|
|Area||52,830 acres (213.8 km2)|
|Established||July 1, 1941|
|Visitors||533,206 (in 2018)|
|Governing body||National Park Service|
|Website||Mammoth Cave National Park|
|Criteria||Natural: vii, viii, x|
|Inscription||1981 (5th Session)|
Since the 1972 unification of Mammoth Cave with the even-longer system under Flint Ridge to the north, the official name of the system has been 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.