Natural stone arches and fantastic rock formations, sculpted as if by an artist's hand, are the defining features of this park, and they exist in remarkable numbers and variety. Just as soon as you've seen the most beautiful, most colorful, most gigantic stone arch you can imagine, walk around the next bend, and there's another -- bigger, better, and more brilliant than the last. It would take forever to see them all, with more than 2,000 officially listed and more being discovered, or "born," every day.

Just down the road from Canyonlands National Park, Arches is more visitor-friendly, with relatively short, well-maintained trails leading to most of the park's major attractions. It's also a place to let your imagination run wild. Is Delicate Arch really so delicate? Or would its other monikers (Old Maid's Bloomers and Cowboy Chaps) be more appropriate? And what about those tall spires? You might imagine they're castles, giant stone sailing ships, or the petrified skyscrapers of some ancient city.

Exploring the park is a great family adventure. The arches seem more accessible and less forbidding than the spires and pinnacles at Canyonlands and most other western parks. Some think of arches as bridges, imagining the power of water that literally cuts a hole through solid rock. Actually, to geologists there's a big difference. Natural bridges are formed when a river cuts a channel; the often bizarre and beautiful contours of arches result from the erosive force of rain and snow, freezing and thawing, as it dissolves the "glue" that holds sand grains together and chips away at the stone.

Although arches usually grow slowly -- very slowly -- occasionally something dramatic happens, like that quiet day in 1940 when a sudden crash instantly doubled the size of the opening of Skyline Arch, leaving a huge boulder lying at its feet. Luckily, no one (that we know of) was standing underneath at the time. The same thing happened to the magnificently delicate Landscape Arch in 1991, when a slab of rock about 60 feet long, 11 feet wide, and 4 1/2 feet thick fell from its underside. Today, it's hard to believe that such a thin ribbon of stone can continue hanging on at all.

Spend a day or a week here, exploring the terrain, watching the rainbow of colors deepen and explode with the long rays of the setting sun, or glimpsing ribbons of moonlight on tall sandstone cliffs. Be on the lookout for mule deer, cottontail rabbits, and bright-green collared lizards as they go about the task of desert living. And let your imagination run wild among the Three Gossips, the Spectacles, the Eye of the Whale, the Penguins, the Tower of Babel, and the thousands of other statues, towers, arches, and bridges in this remarkable sandstone playground.