Cave Dwellings, Montezuma National Monument
Montezuma Castle National Monument protects a set of well-preserved Ancestral Puebloan cliff dwellings near the town of Camp Verde, Arizona, United States. The dwellings were built and used by the Sinagua people.
It is one of the best-preserved cliff dwellings in North America, in part because of its ideal placement in a natural alcove that protects it from exposure to the elements. The precariousness of the dwelling's location and its immense scale - almost 4,000 square feet (370 m2) of floor space across five stories - suggest that the Sinagua were daring builders and skilled engineers. Access into the structure was most likely permitted by a series of portable ladders, which made it difficult for enemy tribes to penetrate the natural defense of the vertical barrier. [Ref. Wikipedia]