Pueblo Bonito (Spanish for "beautiful town"), perhaps the best known of all Chacoan great houses, and located at the center of Downtown Chaco, is less than a half mile from Pueblo Alto, Chetro Ketl, Pueblo del Arroyo, Kin Kletso, and Casa Rinconada. Though it covers somewhat less ground space than Chetro Ketl, this D-shaped great house is the largest of all Chacoan great houses with almost 700 rooms, 32 kivas, and 3 great kivas.
Pueblo Bonito rose four stories on the north back wall and terraced down toward the plaza on three sides, taking advantage of passive solar heating as the winter sun sank low on the southern horizon. The plaza was closed on the south side by a row of rooms, and two walled trash mounds lay just outside the plaza enclosure. At least one Chacoan road approaches the building from the north, and there is good evidence for a road linking Pueblo Bonito with Casa Rinconada, the isolated great kiva on the opposite side of the canyon.
Pueblo Bonito was the object of two major excavation programs and, with the possible exception of Kin Kletso, is the most completely excavated of any great house in Chaco Canyon. As a result, its 300-year construction history is known in great detail. Beginning in the mid-800s as a large arced room block that rose three stories on the north, the structure was remodeled and enlarged at least seven times. Pueblo Bonito architects retained the original arced ground plan even while construction of most great houses in the early 1000s became more rectangular. However, the wings added to Pueblo Bonito at that time did conform to the new order. Final construction at the site occurred in the late 1000s and early 1100s.
Pueblo Bonito was the first Chacoan great house to be excavated. Richard Wetherill and the Hyde Exploring Expedition carried out seasonal work at the site from 1897 to 1900, opening 189 rooms and several kivas in the process. Neil Judd then conducted work in other parts of the building from 1921 to 1927. Minor work has been done at the site since that time by the National Park Service, some of the most significant being the collection by Thomas Windes and several colleagues of new tree-ring samples. This work proved that the building had been started in the 850s, almost seventy years earlier than previously thought.
Text from Ancient Ruins of the Southwest - David Grant Noble 2000.