Mammoth Cave - Mammoth Passage: The Mammoth Caves are huge, so we did two of the tours they offered. They have a whole list of them, but this was all we could afford, and that the kids could handle. This you go in through a natural entrance, so you just walk do the hill and there it is. The tour takes you though one of the largest rooms in the cave, and shows you where they did some of their mining for stuff to make gunpowder out of during the war of 1812. Almost all of the Mammoth Cave system is dry caves, so there weren't any formations in this area, but it was impressive for the sheer size of it.