In the southeastern corner of the state, Carlsbad Caverns National Park is one of the most impressive series of limestone caves in the world. Carlsbad is a three-level cavern that contains the largest known underground room in the world (300 ft/92 m high by 1,500 ft/458 m long by 300 ft/92 m wide). It's an immense, cathedral-like chamber—truly an extraordinary sight. Allow most of the day to see the caverns. The Natural Entrance Tour and the Big Room Tour can be taken without a guide. There are lots of guided tours available, as well, some of them quite strenuous. Strollers are not allowed, and pets must be placed in a kennel.
Be sure to take a long-sleeved shirt or sweater (the temperature is 56 F/13 C year-round down in the caverns) and wear rubber-soled shoes—the walkways may be slippery and damp. There is an underground lunchroom (sandwiches and soft drinks) if your own hollow caverns start rumbling, although some people like to take their own food. If you're there during the summer, don't forget to hang around for the daily emergence of hundreds of thousands of Mexican freetail bats at twilight. (It's very popular, so arrive early if you want to get a seat.) The national park also hosts a weekend predawn Bat Flight Breakfast in August.
If you've got the time, we especially recommend the daily lantern-light guided tours of nearby Slaughter Canyon Cave (approximately 25 mi/40 km of winding road southwest of the Carlsbad Caverns visitors center). It has a host of impressive formations, but be aware that it takes a strenuous, 45-minute hike to get up to the cave after you've parked your car.
The Living Desert Zoological-Botanical State Park in Carlsbad highlights species native to the Southwest that you view while following self-guided trails. Every May, the Mescalero Apache hold their Mescal Roast and Mountain Spirit Dances at the Living Desert Zoo, which includes dances, seminars and a dinner. (Note that the spirit dances don't have any connection to the alcoholic spirit named mescal: Instead, they honor the mescal plant that was a staple of the Apache diet.)
The Bitter Lake National Wildlife Refuge, 80 mi/130 km north, is a wintering ground for sandhill cranes and also hosts at least 300 other species of birds—including roadrunners. Carlsbad Caverns National Park is 245 mi/395 km southeast of Albuquerque.