The Chankillo Archaeological Site is situated in a coastal desert in the Ancash region of Peru. Constructed in the fourth century BC, it has been interpreted as a fortified temple complex that includes a solar observatory known as the "Thirteen Towers."
Chankillo Archaeological Site
The Chankillo (or "Chanquillo") Archaeological Site is situated below the western slopes of the Andes, in a coastal desert near the Casma-Sechín river basin, in the Ancash region of Peru. It is located approximately 14 km (9 mi) from the coast of the Pacific Ocean.
Chankillo is a World Heritage Site. In 2021, the site was inscribed on the UNESCO World Heritage List as the "Chankillo Archaeoastronomical Complex."
Chankillo, built in the fourth century BC by the Casma/Sechin culture, covers about 4 sq km (1.5 sq mi) and has been interpreted as a fortified temple. It includes residential areas, a hilltop fort, a solar observatory known as the "Thirteen Towers" and observation platforms.
Recent excavations indicate that the site was occupied for a relatively short period of time between the mid-fourth century BCE and the early first century CE but was subsequently abandoned. It remained largely forgotten until the nineteenth century.
In 2007, archaeological evidence was interpreted suggesting that Chankillo and the Thirteen Towers had been a solar observatory capable of tracking the solstices and the equinoxes. If so, it would be the oldest of its kind in the Americas.
Archaeological evidence at the site also suggests that sun worship existed in the Andes around two millennia before the well-known sun cult of the Inca Empire.
Thirteen Towers of Chankillo
The Thirteen Towers of Chankillo were constructed between two observation platforms in order to span the entire annual rising and setting arcs of the sun, which gradually shift along the horizon over the course of a year.
On the winter solstice, the sun would rise behind the left or northernmost tower and eventually rise behind each successive tower until it reached the right or southernmost tower six months later on the summer solstice.
By observing the rising sun and setting sun from the correct tower, the date could be determined within one or two days precision, which is unique among ancient observatory sites.