Chankillo Archaeoastronomical Complex

Chankillo lies in a desert landscape in the Casma Valley on Peru’s north-central coast. The UNESCO property includes a triple-walled hilltop structure known as the Fortified Temple, an Observatory, an Administrative Centre, the Thirteen Towers along a ridge, and Cerro Mucho Malo, which acts as a natural marker. Together, constructed and natural features formed a calendrical instrument based on the Sun.

The towers form a north–south line along a low ridge. Archaeological and archaeoastronomical studies describe observation points on both sides of the line, from which the towers mark the changing positions of sunrise and sunset over the year. UNESCO says the artificial horizon could mark solstices, equinoxes and dates throughout the year with an estimated precision of one to two days. The arrangement therefore worked as a year-round solar calendar rather than aligning with only one astronomical event.

UNESCO dates the prehistoric complex to 250–200 BCE and says it was used for a relatively brief period before being destroyed and abandoned. The ceremonial centre was probably dedicated to a solar cult, though this interpretation is expressed cautiously. In 2021, the World Heritage Committee inscribed the property under cultural criteria (i) and (iv), recognizing its exceptional example of ancient landscape timekeeping and its importance in the development of astronomy in the Americas.

The site is a protected national cultural heritage property in Peru and has a management plan. UNESCO notes conservation challenges, including deterioration of structural elements and the need to protect the sightlines and surrounding setting. The World Heritage Committee has called for long-term conservation, continued research, local community involvement and careful assessment of development and visitor-related pressures.