Mammoth Cave National Park

Mammoth Cave National Park is a U.S. National Park in central Kentucky, encompassing portions of Mammoth Cave, the most elongated cave system known in the world. The official name of the system is the Mammoth Cave System, though it could be argued that it should be called the Flint-Mammoth-Toohey-Eudora-Joppa-Jim Lee Ridge Cave System—to account for the ridges under which the cave has formed. The park was established as a national park on July 1, 1941. It became a World Heritage Site on October 27, 1981, and an international Biosphere Reserve on September 26, 1990. The park's 52,830 acres (214 km²) are located in Edmonson County, Kentucky, with small areas extending eastward into Hart County and Barren County. It is centered around the Green River, with a tributary, the Nolin River, feeding into the Green just inside the park. The Green River is dammed near the western boundary of the park, so that the river only flows freely for a small section in the eastern part of the park.