After a long trek through rugged forest terrain, we finally arrive at the entrance to a deep pit cave. The scene is already active - friends of ours are inside, maneuvering their way back up from ...

Mammoth Cave, located in Mammoth Cave, Kentucky, is known as the largest haunted cave in America ... the brothers saw some grass blowing near the cave entrance, which was a hole in the ground.

Located about a 45-minute drive from the park's main entrance, near Giant Forest, Crystal Cave was carved into existence over millions of years by underground streams eroding the marble.