Chankillo: Thirteen Towers That Turned the Sun into Power

Chankillo is an archaeological site in the Casma Valley on the north-central coast of Peru. Its main structures went up around the fourth century BCE, about 2,300 years ago. Along a low ridge running close to a north-south line stand thirteen stone-and-mortar towers, spread over roughly 300 metres. Temples, walls, courtyards, and observation points surround the tower line.

The towers were built into the Sun's yearly path, and that placement drives everything else at the site. From fixed viewing points to the east and to the west, an observer watches the Sun rise or set beside one tower and then beside the next as the year moves on. The line works as a calendar anyone can see: a stone horizon carrying fixed markers against which anyone can check the Sun's position. Archaeologists Iván Ghezzi and Clive Ruggles published this reading in 2007, and UNESCO now records Chankillo as a calendrical instrument that used the Sun to identify dates through the seasonal year. If the Sun's position decides when a festival opens, when workers are called out, and when the food stores open, the thirteen towers turned the Sun into power, and every part of the site fits how such a machine runs.