The social and ritual context of horizon astronomical observations at Chankillo

Abstract

AbstractThe authors have shown previously that, as viewed from an evident observing point to the west, and a plausible observing point to the east, the Thirteen Towers of Chankillo formed an artificial ‘toothed’ horizon that spanned the annual rising and setting arcs of the sun and provided a means to identify each day in the seasonal year by observing the position of sunrise or sunset against them. The Thirteen Towers thus constitute a unique solar observation device that is still functioning, and a remarkable example of a native form of landscape timekeeping that preceded similar facilities in imperial Cusco by almost two millennia. Yet the social, political, and ritual contexts in which Chankillo's astronomical alignments operated deserve further exploration. In this paper, we present new archaeoastronomical evidence that not only clarifies some aspects of the solar observation device but suggests a wider range of alignments visible from more publicly accessible parts of the ceremonial complex, and also suggests a possible interest in marking lunar alignments as well as solar ones. We also bring together archaeological evidence to suggest that the society that built Chankillo was differentiated. The Thirteen Towers may have served to regulate the calendar, solar and ritual, while the solar cult centred on them may have lent legitimacy and authority to a rising warrior elite through ceremony in an impressive sacred setting that brought society together while reproducing its growing inequality.