Arguably the most memorable natural area in this part of the Southwest, White Sands National Monument preserves the best part of the world's largest gypsum dune field, an area of 275 square miles of pure white gypsum sand reaching out over the floor of the Tularosa Basin in wavelike dunes. Plants and animals have evolved in special ways to adapt to the bright white environment here. Some creatures have a bleached coloration to match the whiteness all around them, and some plants have evolved means for surviving against the smothering pressures of the blowing sands.

The surrounding mountains -- the Sacramentos to the east, with their forested slopes, and the serene San Andres to the west -- are composed of sandstone, limestone, sedimentary rocks, and pockets of gypsum. Over millions of years, rains and melting snows dissolved the gypsum and carried it down into Lake Lucero. Here the hot sun and dry winds evaporate the water, leaving the pure white gypsum to crystallize. Then the persistent winds blow these crystals, in the form of minuscule bits of sand, in a northeastern direction, adding them to growing dunes. As each dune grows and moves farther from the lake, new ones form, rank after rank, in what seems an endless procession.

The dunes are especially enchanting at sunrise and under the light of a full moon, but you'll have to camp here to experience this extraordinary sight. If you're not camping, you'll probably want to spend only a couple of hours here. Refreshments and snacks can be purchased at the visitor center, along with books, maps, posters, and other souvenirs; however, no dining or grocery facilities are available here.