The national park entrance is about a half hour drive south of the town of Carlsbad. A seven mile road leads from the park entrance up into the mountains to the visitor center and cavern entrance. The caverns are open every day (except Christmas Day) from 8:00 to 5:00 pm.  Several different tours are offered, and you should check the one that meets your interest and capabilities. Some tours are not so good for kids, or adults in less than ideal phsycial condition, or those with knee problems. You may enter the cave by walking along the natural entrance route, descending 750 feet (sloping walkways, not stairways, but may be hard on knees of older people) to the lunchroom and start of the Big Room self-guided tour. The lunch room includes sandwiches and soft drinks, a small assortment of souvenirs, as well as restrooms (amazing, considering you are 750 feet under the desert!). You may enter the self guided natural entrance route until 2 pm, or take an elevator from the visitor center. The ride takes about one minute, and the last one is offered at 3:30 pm. The natural entrance route will take about 45 minutes, unless you linger. The Big Room will take about an hour to really enjoy. Part of the Big Room route is wheelchair accessible. Many of the formations are huge and breath taking! Rangers are posted along the routes to answer questions, or you may rent an audio program at the visitor center, which allows you to carry a light-weight plastic "stick", and press buttons corresponding to signs in the cave, activating entertaining and informative audio segments which tell you about the cave's various features. The audio "sticks" are well worth the price. Pay extra and reserve your spot for guided tours of the Kings Palace and other places. On the surface, you can see the Guadalupe Mountains to the south in a grand vista. The visitor center features a nice book store, gift shop, and cafetera (I visited in 2002, so please edit this if the amenties for visitors have changed). I am not familiar with surface features, but apparently the park offers a scenic desert drive and trails. Be aware of the harsh environment, and carry plenty of water and sunscreen, and dress accordingly. In the evenings between May and October, thousands of Mexican freetail bats spiral up in great numbers from the cavern mouth, and just prior to the flight, a ranger conducts a bat-flight program in the large stone amphitheater. The talk is full of interesting facts about the bats. The program was very entertaining, as the ranger had the audience play a "Who Wants to be a Bat Millionaire?" game! Her enthusiasm was contagious, but it ended abruptly when the first bats appeared, because she had warned  that the first fliers would be senstive to outside conditions, and could warn the others to spend the night in the cave if outside conditions were not ideal. That would be really bad for the bats, because each one eats about its own weight in insects while it flies around the area each night. They really need their nightly feeding! In the morning, the bats do not need to spiral down. They dive nearly straight down into the huge cavern mouth, putting on a different kind of show in reverse. The evening bat flight is truly amazing. As you sit  in the amphitheater, several of them may flutter up within a few feet of you, but you do not need to worry. They are not interested in you at all. They simply want to devour vast quantities of insects. Watching the flight of hundreds of thousands of bats (heaviest in August after babies have been born) is an experience you will not soon forget. Overall, Carlsbad Caverns is spectacular. Also visit nearby White Sands National Monument near Alamogordo (3 1/2 hours away by car), and the UFO museum at Roswell (about a one hour drive north of Carlsbad).