Arizona's Grand Canyon -- 280 miles long, up to 18 miles wide and more than a mile deep -- may be the world's most famous canyon. But the southwest United States is home to many other spectacular canyons, many of them concentrated in the parks and wilderness areas of southern Utah. Among them:

Canyonlands National Park, in southeast Utah. Most of this 500-square-mile park is wilderness -- it's a wild, primitive place, much of it accessible only by four-wheel-drive vehicles or on foot. Featuring magnificent canyons cut by the Colorado and Green rivers, the park's attractions include the Island in the Sky, a sheer-sided plateau that towers 2,000 vertical feet; innumerable geological formations; and prehistoric Indian ruins and pictographs. Information: Canyonlands National Park, 125 West, 200 South, Moab, Utah 84532, (801) 259-8415.

Zion National Park, southeast of Cedar City. This 229-square-mile park features canyons, gorges, sheer rock walls and unique formations cut by the Virgin River. The main road and most of the visitor facilities are on the canyon floor; the scenic road through Zion Canyon, more than six miles long, is enclosed by sheer, varicolored cliffs. Information: Zion National Park, Springdale, Utah 84767, (801) 772-3256.

Bryce Canyon National Park, east of Cedar City. The Paiute Indians called this 56-square-mile area "red rocks standing like men in a bowl-shaped canyon," which is as good a description as any: It's a great natural amphitheater with towering stone columns, spires and other fantastic sculptures. You can see it by car -- a paved road skirts the western rim for 20 miles -- but to truly appreciate the beauty of the formations, take one of the trails, which range from 1 1/2 to 23 miles long. Information: Bryce Canyon National Park, Bryce Canyon, Utah 84717, (801) 834-5322.

Capitol Reef National Park, east of Torrey. Capitol Reef is a rugged, harsh land of rocky gorges, soaring arches and sandstone monoliths. The "capitol" comes from the park's rounded sandstone domes; the "reef" is Waterpocket Fold, a 100-mile-long upthrusted ridge of rock. Most of the roads in the 378-square-mile park are unpaved, but there are trails for fine (if rugged) back-country hiking. Information: Capitol Reef National Park, Torrey, Utah 84775, (801) 425-3791.

Cedar Breaks National Monument, between Bryce Canyon and Cedar City. A six-mile paved rim road overlooks a huge, eroded amphitheater, with walls dropping more than 2,000 feet to the valley below. With overlooks and hiking trails through the canyons. Information: Cedar Breaks National Monument, P.O. Box 749, Cedar City, Utah 84720, (801) 586-9451.