Carlsbad Caverns National Park was established to preserve Carlsbad Cavern and numerous other caves within a Permian-age fossil reef. The park contains 83 separate caves, including the nation's deepest limestone cave -- 1,597 feet -- and third longest. Carlsbad Cavern, with one of the world's largest underground chambers and countless formations. It is also highly accessible, with a variety of tours offered year-round.

The evening flight of Mexican free-tailed bats (Tadarida brasiliensis mexicana) from the entrance of Carlsbad Cavern is one of the park's principal visitor attractions. Free-tailed bats are a colonial species that feed entirely on insects. The colony at Carlsbad is comprised primarily of females who give birth to their young from June through July before migrating south in October to winter in Mexico.