Once you are ready to start your tour, you will take an elevator deep into the earth to the level of the caverns. You can choose as you take the tour how long you want to go because there is a route for a short tour and a continuation route for a long tour. My wife is afraid of heights, so we only toured the Big Room. It had a large variety of formations and they were many colors. At some points, the trail through the cavern came to some fairly high drop-offs, but my wife held to me and was able to get past them. The inside of the cavern has a pretty good artificial lighting system, but it could be better.

We really enjoyed the tour; however, I would recommend a tour of Natural Bridge Caverns north of San Antonio, TX. The cave is not nearly as big as the big one at Carlsbad, but it has some beautiful formations. I thought the color and variety of the Natural Bridge formations were better.

The caverns encompass vast caves, both developed and undeveloped. The main chamber -- "Big Room" -- is the most accessible (even to wheelchairs). Measuring 1800 feet by 1000 feet, with the ceiling in some spots reaching to nearly 300 feet, "Big Room" is aptly named. The walkway wends around the perimeter of the chamber, revealing exotic sights both minute and grand.

Glittering calcite stalactites dripping from the ceiling, popcorn-like rocks covering the ground, the enormity of it all dwarfing you . . . words can't capture the awe one feels.

The most surreal aspect of the experience for me was the uncanny feeling that I was underwater. Gazing up at arching ceilings, looking down on formations reminiscent of coral reefs, following the undulating currents of the path, perceiving the not-unpleasant sensation of being enclosed, I could not help but feel I was scuba diving through some fantastic undersea landscape.

We arrived late and only had the self-guided tour of the Natural Entrance and the Big Room, and it took us nearly 3 hours. If you have time and energy, the park rangers offer guided tours of other caverns for a fee. The brochure mentioned six different tours for various prices; however, I believe the most popular guided tour is the King's Palace for $8.

My brother and his wife visited the caverns a week before Labor Day and were able to tour till 7pm. However, when we visited right after Labor Day, the winter hours were observed and the last entrance to the Natural Entrance was at 2pm, to the King's Palace was at 2:30pm and to the Big Room was at 3:30pm. Both in the Natural Entrance cavern and the Big Room, rangers warned us to be swifter.

We had been in other caverns in Virginia, but none of them could compare to the Carlsbad Caverns. Not only was the size of the caverns enormous, but also, the lighting was very dim, which enhanced our experience. Even the entrance to the Natural Entrance was very impressive. From a big opening we entered the cave. The paved trail curved into the depths of the cavern. First we could see in natural light; later it was like dusk, and finally the only light available was the electrical lights. After 750 feet of descent, the cavern floor leveled and we entered the Big Room. The Big Room was big enough to have eight football fields in it! Although it had more lighting, it still had an overpowering atmosphere. I felt scared when we didn't see anyone for more than five minutes. I was tired and relieved when we ascended to ground level by the elevator. There is an "Underground Lunchroom" and restrooms in the caverns near the elevator.

At 6:30pm there was a special program "Bat Flight" in the amphitheater next to the entrance of the caverns. (This is from mid-May to mid-September. After September the bats migrate to Mexico.) A ranger gave a fun lecture on Mexican Freetailed Bats and answered our questions. It was very fun to watch the flight of the bats at dusk. There were nearly 30,000 bats roosting in the Carlsbad Caverns (no need to worry, the trails do not go under the bats). At dusk they leave the caverns and fly away to find food.