Pueblo Bonito was a monumental Chacoan great house that served surrounding communities and the region when Chaco was a major center of Puebloan culture between A.D. 850 and 1150. It fulfilled many roles, including ceremony, administration, trading, storage, hospitality, communications, astronomy, and burial of the honored dead, while only a small portion appears to have been used as living quarters. More than 600 rooms rose four and five stories above the valley floor and covered 3 acres. Its distinctive D-shaped form enclosed two plazas with dozens of ceremonial kivas, and straight avenues connected it with nearby and distant great houses.