Scuba dive in the desert? You bet. One of the grandest natural spring-fed pools in the world, San Solomon Springs, is in Balmorhea State Park. Fluctuating between 72 and 76 degrees, with a constant influx of pellucid spring water, the pool needs no chlorination. Once the haunt of the Mescalero Apaches, the spring now hosts abundant wildlife, including turtles, crayfish, and an endangered pupfish. Peruse them underwater with an air tank or snorkel, as many visitors enjoy doing. Though deep enough to amuse expert divers (30 feet in some spots), the spring also has shallow areas ideal for novices. Rustic cottages welcome travelers who want to stay overnight.