Laurel Caverns is a large natural calcareous sandstone cave located 50 miles south of Pittsburgh. Most of the passage ceilings in its four mile labyrinth are between ten and twenty feet high (many as high as 50 feet) with an average width of over twelve feet. This makes it the largest cave in Pennsylvania. If classified as a sandstone cave, it is the largest sandstone cave in the world. The cave itself is situated beneath a 435 acre privately owned geological preserve. Because this property is at the top of Chestnut Ridge, all of the water that enters the cave is pristine.