Mesa Verde NP, Colorado

10. Cliff Dwellings

Spruce Tree House, the third largest cliff dwelling (Cliff Palace and Long House are larger), was constructed between AD 1211 and 1278 by the ancestors of the Puebloan peoples of the Southwest. The dwelling contains about 130 rooms and 8 kivas, or ceremonial chambers, built into a natural cave measuring 216 feet (66 meters) at greatest width and 89 feet (27 meters) at its greatest depth. It is thought to have been home for about 80 people.