Most visitors to Cusco, Peru, are aware that the Inca studied and worshipped the cosmos. For those who stroll about the historic Plaza de Armas, it’s practically common knowledge that, five hundred years ago, Inca priests predicted astronomical events with great precision, and that their engineers built temples and roads that aligned perfectly with these phenomena. But one feat of Inca astronomy and engineering that’s perhaps less well known is the sun towers that may have once marked such cosmic events from atop the ridges surrounding Cusco.
According to Spanish accounts from the 1500s, as many as 16 of
