2. Mammoth Cave National Park, Kentucky
Mammoth Cave might just be the most haunted place in the US, with more that 150 documented paranormal events in the area. Of the many stories and strange events linked to the cave, the most frequent sighting is of Stephen Bishop, a slave and cave guide described as “one of the greatest explorers Mammoth Cave has ever known” by the National Park Service website. He is said to help lost explorers find their way in the intricate maze of passageways in the cave.