thumb|432x432px|Cliff Palace, Mesa Verde National Park
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 Montezuma County, in the southwestern corner of Colorado, Southwestern United States.
History
It is believed that Cliff Palace was constructed and lived in from about 1200 A.D. to 1300 A.D. Cliff Palace was abandoned by 1300, though debate is ongoing as to the cause. Some contend that a series of megadroughts interrupting food production systems was the main cause. Wetherill and Mason also rediscovered Spruce Tree House and Square Tower House, which are also located in Mesa Verde. According to Wetherill and Mason, they "followed the Indian trail down Chapin Mesa, between Cliff and Navajo canyons, and camped at the head of a small branch of the Cliff Palace fork of Cliff Cañon." Wetherill and Mason spent time after finding the dwellings looking at artifacts found within the cliff. According to Mason, they found a stone axe "with the handle still on it" and also observed "parts of several human skeletons scattered about."
Many visitors wonder about the relatively small size of the doorways at Cliff Palace. At the time when Cliff Palace was constructed, the average man was about tall, while the average woman was about tall. Archaeologists believe that Cliff Palace contained more clans than the surrounding Mesa Verde communities. This belief stems from Mesa Verde's 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.
Excavation
Even though Cliff Palace was rediscovered in 1888, it was not formally excavated by an archeologist until 1906, when Mesa Verde National Park was established. In order to actually go into the site, one must obtain a ticket for a ranger-guided tour. The tour season runs from May through October, and one tour is limited to fifty visitors.