Cliff Palace is the largest cliff dwelling in North America. The structure built by the Ancestral Puebloans is located in Mesa Verde National Park in their former homeland region. The cliff dwelling and park are in the southwestern corner of Colorado, in the Southwestern United States.
Tree-ring dating indicates that construction and refurbishing of Cliff Palace was continuous approximately from 1190 CE through 1260 CE, although the major portion of the building was done within a 20-year time span. The Ancestral Pueblo that constructed this cliff dwelling and the others like it at Mesa Verde were driven to these defensible positions by "increasing competition amidst changing climatic conditions". Cliff Palace was abandoned by 1300, and while debate remains as to the causes of this, some believe that a series of megadroughts interrupting food production systems is the main cause. Cliff Palace was rediscovered in 1888 by Richard Wetherill and Charlie Mason while out looking for stray cattle.
Cliff Palace was constructed primarily out of sandstone, mortar and wooden beams. The sandstone was shaped using harder stones, and a mortar of soil, water and ash was used to hold everything together. "Chinking" stones were placed within the mortar to fill gaps and provide stability. Many of the walls were decorated with colored earthen plasters, which were the first to erode over time. Many visitors wonder about the relatively small size of the doorways at Cliff Palace; the explanation being that at the time the average man was under 5 feet 6 inches (1.68 m), while the average woman was closer to 5 feet (1.5 m). Cliff Palace contains 23 kivas (round sunken rooms of ceremonial importance) and 150 rooms and had a population of approximately 100 people. One kiva, in the center of the ruin, is at a point where the entire structure is partitioned by a series of walls with no doorways or other access portals. The walls of this kiva were plastered with one color on one side and a different color on the opposing side. It is estimated that around 100 people inhabited Cliff Palace during its time of use. "It is thought that Cliff Palace was a social, administrative site with high ceremonial usage."Archaeologists believe that Cliff Palace contained more clans than the surrounding Mesa Verde communities. This belief stems from the higher ratio of rooms to kivas. Cliff Palace has a room-to-kiva ratio of 9 to 1. The average room-to-kiva ratio for a Mesa Verde community is 12 to 1. This ratio of kivas to rooms may suggest that Cliff Palace might have been the center of a large polity that included surrounding small communities.