The position of a building, carving or sightline can reveal that people paid attention to the Sun, Moon or stars. At Chaco Canyon in the American Southwest, researchers have studied alignments associated with seasonal celestial events. Such evidence can lead to questions about timekeeping, ceremony and the organisation of a place.
An alignment alone is not a complete explanation of what it meant to its makers. Researchers compare it with other archaeology, the local landscape and, where appropriate, knowledge held by descendant communities.