Mammoth Cave National Park is a national park in the United States in central Kentucky which comprises the longest cave system known in the world. It is now a world heritage site and was given this honor on the 27th October 1981. The park was established as a national park on the 1st of July 1941.  There is a myth that the cave gets its name from Mammoth fossils but no such fossil has been found. The term mammoth merely refers to its huge size.