Mesa Verde National Park

In southwestern Colorado, about four hours north of Albuquerque, Mesa Verde protects nearly 600 cliff dwellings built by the Ancestral Puebloans, a UNESCO World Heritage Site. Cliff Palace, the largest, holds more than 150 rooms and 23 ceremonial kivas beneath a single great sandstone arch. Ranger led tours climb ladders and stone steps into the dwellings, the only way inside, and tickets sell out fast. May through October is tour season, and the park sits on the classic Four Corners driving circuit with Monument Valley and Chaco.