Mesa Verde Cliff Dwelling

Cliff dwelling is the general archaeological term for the habitations of prehistorical peoples, formed by utilizing niches or caves in high cliffs, with more or less excavation or with additions in the way of masonry.

Cliff Palace is the largest cliff dwelling in North America. The Ancient Pueblo structure is located in Mesa Verde National Park, in the southwest corner of the U.S. state of Colorado, home to the Ancestral Puebloans people.

Read more on Wikipedia

More info:
Mesa Verde Cliff Dwelling
Mesa Verde Cliff Dwelling
Greatbuildings.com

Photos: Wikipedia