The Carlsbad Caverns National Park contains 113 of more than 300 known caves beneath the surface of the Chihuahuan Desert and Guadalupe Mountains of southeastern New Mexico and west Texas. All caves was formed as sulfuric acid dissolved the surrounding limestone. The most famous part of this National Park is the show cave, which is open to the public and tourists can hike by themselves via the natural entrance. National Park was first designated a National Monument on 25 Oct 1923. Carlsbad Caverns was also designated a World Heritage Site on 06 Dec 1995.