One of the largest and most spectacular cave systems in the world, Carlsbad Caverns National Park comprises more than 100 known caves that snake through the porous limestone reef of the Guadalupe Mountains. Fantastic and grotesque formations fascinate visitors, who find every shape imaginable (and unimaginable) naturally sculpted in the underground -- from frozen waterfalls to strands of pearls, soda straws to miniature castles, draperies to ice-cream cones. Plan to spend a full day.
Formation of the caverns began some 250 million years ago, when a huge inland sea covered this region. Then, about 20 million years ago, a reef that was once undersea moved upward, ultimately breaking free of thousands of feet of sediment enshrouding it. As tectonic forces pushed the buried rock up, erosion wore away softer minerals, leaving behind the Guadalupe Mountains. Brine from gas and oil deposits mingled with rainwater, creating sulfuric acid that dissolved limestone and created cave passages.
Once the caves were hollowed out, nature became artistic, decorating the rooms with a vast variety of fanciful formations. Very slowly, water dripped down through the rock into the caves, dissolving more limestone and absorbing the mineral calcite and other materials on its journey. Each drop of water then deposited its tiny load of calcite, gradually creating the cave formations we see today.
Although American Indians had known of Carlsbad Cavern (the park's main cave) for centuries, it was not discovered by settlers until ranchers in the 1880s were attracted by sunset flights of bats emerging from the cave. The first reported trip into the cave was in 1883, when a man supposedly lowered his 12-year-old son into the cave entrance. A cowboy named Jim White, who worked for mining companies that collected bat droppings for use as a fertilizer, began to explore the cave in the late 1800s. Fascinated by the formations, White shared his discovery with others, and soon word of this magical below-ground world spread.
Carlsbad Cave National Monument was created in October 1923. In 1926, the first electric lights were installed, and in 1930 Carlsbad Caverns gained national park status.
Underground development at the park has been confined to the famous Big Room, one of the largest and most easily accessible of the caverns, with a ceiling 25 stories high and a floor large enough to hold six football fields. Visitors can tour parts of it on their own, aided by a state-of-the-art portable audio guide, and explore other sections and several other caves on guided tours. The cave is also a summer home to about 300,000 Mexican free-tailed bats, which hang from the ceiling of Bat Cave during the day, but put on a spectacular show each evening as they leave the cave in search of food, and again in the morning when they return for a good day's sleep.