
The Bottomless Pit in Carlsbad Caverns National Park is not actually bottomless, but rather about 140 feet (43 meters) deep. Early explorers, however, found the pit to be daunting and named it accordingly. The ladder you see in the photo was not necessarily built to explore the entirety of the pit, but more to simply explore more of the cave, itself. Personally, I think I would take a pass on using the ladder.