Montezuma Castle National Monument, 858 acres (347 hectares), central Ariz.; est. 1906. Montezuma Castle, built c.1250, is a 5-story, 20-room dwelling perched high in the cavity of a cliff. It was named by early settlers who believed it had been built by the Aztecs. See National Parks and Monuments (table). In the region are other well-preserved cliff dwellings of prehistoric Native American groups (see cliff dwellers).