Criterion (i): Chankillo Archaeoastronomical Complex is an outstanding example of ancient landscape timekeeping, a practice of ancient civilizations worldwide, which used visible natural or cultural features. Incorporated in the Thirteen Towers, it permitted the time of year to be accurately determined not just on one date but throughout the seasonal year. The astronomical facilities at Chankillo represent a masterpiece of human creative genius. The Chankillo Complex is a very particular type of building representing an early stage in the development of native astronomy in the Americas. IntegrityAll the elements necessary to express the Outstanding Universal Value of Chankillo Complex centred on calendrical observations of the sun are included within the property boundaries.