Pueblo Bonito, the largest and best-known great house in Chaco Canyon, was built in stages by Ancestral Puebloans between about AD 850 and 1150 and occupied from AD 828 to 1126. Covering roughly 3 acres with about 800 rooms, multiple kivas, and tiered masonry rising as high as five stories, it was a monumental center in the Chacoan world. Evidence suggests it served less as a densely populated village than as a ritual and political center, linked to solar and lunar alignments, long-distance exchange including cacao from Mexico, and an elite matriline. Its architecture, burials, and environmental record make it crucial to understanding Chaco society.