PUEBLO BONITO (Pretty Village or Beautiful Town)
Construction of Pueblo Bonito (Pretty Village or Beautiful Town) occurred in stages between 850 and 1130 A.D. Pueblo Bonito is a Great House, and the largest structure in Chaco Canyon. There are approximately 3 great kivas, 30 smaller kivas, and almost 700 rooms. The pueblo is massive, once rising to 4 stories and with a perimeter of 1300 feet, approximately the size of the Roman Coliseum. The walls are 2.75 feet thick at the base, tapering as they rise to reduce the load on the foundation. The pueblo is in a "D" shape and situated so that the straight outer wall acts as a solar marker.
Pueblo Bonito may have been used primarily for special occasions such as religious and spiritual ceremonies, or during times of trade when a large influx of people might have visited Chaco Canyon. Judging by the number of fire pits and the size of the trash midden nearby, the permanent population of Pueblo Bonito may have been as few as 50 people.
One outer room in Pueblo Bonito has an unusual east-facing opening in the corner. This appears to be a solar marker. There are many different man-made construction projects that appear to function as solar or lunar markers. Although absolute proof is unobtainable, the number of structures and architectural features that serve as astronomical markers in Chaco Canyon strongly suggest that the people who lived here developed an impressive understanding of astronomy.
Winter Solstice: The winter solstice marks the day when the sun is at its lowest arc in the sky, giving us the longest night and the least amount of daylight.
Summer Solstice: The summer solstice marks the day when the sun is at its highest arc in the sky, giving us the shortest night and the largest amount of daylight.
Equinox: The time when the sun appears directly overhead at the equator, a time when day and night are of equal length.