Carlsbad Caverns National Park, area of the Chihuahuan Desert in southeastern New Mexico, U.S., near the base of the Guadalupe Mountains (a segment of the Sacramento Mountains). It was established in 1923 as a national monument, designated a national park in 1930, and proclaimed a UNESCO World Heritage site in 1995. Beneath the park, which has a surface area of 73 square miles (189 square km), are 83 individual caves, including Carlsbad Cavern, the park’s namesake. The park also includes Rattlesnake Springs, a small enclave about 5 miles (8 km) to the southeast.Carlsbad Cavern has a labyrinth of underground chambers, including one of the largest ever discovered. The total length of the rooms and passages is still unknown, but the explored part of the main cavern is more than 30 miles (48 km) long, of which 3 miles (5 km) are open to visitors. Of the three major levels, the deepest is 1,027 feet (313 metres) belowground.