827. Cliff palace, Mesa Verde,

Colorado, c. 1100-1300 (U.S.A.)

This ancient stone pueblo in southwest Colorado is the largest alcove dwelling in North America. An entire city is located at the top of a sheer cliff face, sheltered by a massive overhang of natural rock. This unusual choice of site offered various advantages, including protection from the colder north winds and inaccessibility to invaders. Its builders were the ancestral Pueblo people, also known as the Anasazi, or ‘Ancient Ones.’ The settlement at Mesa Verde consists of over 200 rooms and 23 kivas; the latter are round-plan structures, developed from an earlier sunken pit house typology, that seem to have served both religious and social functions. The stonework of the Cliff Palace originally had a protective covering of plaster. Everyday life was carried out in the upper stories, while the darker areas below were likely reserved for food storage. The site was abandoned by 1300 for unknown reasons. The Anasazi also established freestanding settlements for trade in the region, notably Pueblo Bonito at Chaco Canyon in New Mexico. Mesa Verde is a US National Park and a UNESCO World Heritage Site.