Chankillo Archaeoastronomical Complex
The Astronomical Archaeological Complex of Chanquilo is a prehistoric site (250-200 BC) located in the Cosma Valley on the north-central coast of Peru, consisting of a group of buildings in a desert landscape that, together with the natural landscape, served as a calendar tool, using the sun to determine dates throughout the year. The site includes a three-walled hilltop complex known as the defensive temple, two complexes known as the observatory and administrative center, a row of 13 cubic towers running along a ridge, and Cerro Muchomaro, a natural landmark that complements the 13 towers. This ritual center was probably built for the worship of the sun, and the 13 towers were flanked by an observation point on each side of the north-south line, allowing the sun's rise and set points to be observed throughout the year. The site demonstrated great innovation in using the solar cycle and an artificial horizon to mark the solstices, equinoxes, and every other date of the year with an accuracy of 1-2 days. As such, it bears witness to the long historical evolution of astronomical practices in the Cosma Valley.