The Thirteen Towers of Chankillo
The Thirteen Towers of Chankillo run north to south along a low ridge within a fourth-century B.C.E. ceremonial complex in north coastal Peru. From evident observing points within the adjacent buildings to the west and east, they formed an artificial toothed horizon that spanned—almost exactly—the annual rising and setting arcs of the Sun. The Chankillo towers thus provide evidence of early solar horizon observations and of the existence of sophisticated Sun cults, preceding the Sun pillars of Incaic Cusco by almost two millennia.
Chankillo is imposing. Rising some 300 meters up from the desert floor, it is perched straddling a hill. Its three concentric walls are permeated by baffled entrances, five on the outer wall, four on the next wall, and three on the innermost wall. The doors open into 90-degree corridors that imply a defensive purpose. However, door slots are found on the outside walls, indicating that doors were tied closed from the outside, adding more fuel to the debate about Chankillo's purpose.
Thirteen Towers sit on a hillcrest across the plain from Chankillo. Each tower is 2-6 meters high, and the construction closely resembles the masonry technique used in the fortress. The number thirteen has always suggested a connection with the lunar calendar.
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