Mammoth Cave is found in South Central Kentucky. The cave in the summers is about 80 degrees and in the winters it is about 40 degrees, deep in the cave the average is 54 degrees at all times.
This is the longest cave system in the world, it is more than 400 miles long. The trails go up to 90 miles deep.
The cave was established in July 1 1941 by John Houchin. While hunting Houchin was following a wounded bear into the entrance of the cave and that's how it was founded.