The most easily accessible of the hundreds of different prehistoric settlements all over the southwestern United States, Walnut Canyon National Monument (928/526-3367, daily 9am-5pm fall-spring, daily 8am-5pm summer, $8) is also one of the prettiest places imaginable, with piñon pines and junipers clinging to the canyon walls, and walnut trees filling the canyon floor. On the edge of the canyon, a small visitors center gives the historical background, but the real interest lies below, on the short but steep Island Trail, which winds through cliff dwellings tucked into overhangs and ledges 400 feet above the canyon floor. Winter storms sometimes dislodge boulders that wipe out parts of the trail. Check with the rangers to make sure the trail is open, and ask about weather, water supplies, and other safety issues. The rim of Walnut Canyon is nearly 7,000 feet above sea level, and the altitude can make the climbing especially strenuous.

The entrance to the Walnut Canyon monument, which contains some 80 dwellings, lies nine miles east of Flagstaff, accessible from I-40 exit 204.