Chaco Canyon, centre of the Ancestral Puebloan world

Ancestral Puebloans built multi-storey great houses in Chaco Canyon, the largest with around 600 rooms, some aligned to solar and lunar cycles and linked to outlying communities by straight roads. Chaco was a ceremonial and trading centre that drew turquoise, macaw feathers and cacao from Mexico. It declined after a long drought in the 12th century.