Walnut Canyon National Monument

Walnut Canyon shelters cliff dwellings built by the Sinagua people between about 1100 and 1250, tucked into alcoves in the canyon's limestone walls. The Island Trail, a 0.9-mile loop, descends 185 feet past 25 dwelling rooms, and the whole monument is an International Dark Sky Park.

Walk the Island Trail's steps into the canyon past the dwelling rooms, then take in the rim overlooks; young kids can earn a Junior Ranger badge. For a challenge, pair the stair-heavy Island Trail with the rim trail, then stay for the monument's famously dark night sky.