Marcahuamachuco, Muros del Castillo

Construction of Marcahuamachuco began around AD 400, during the Andean Middle Horizon period and continued until approximately 800 AD. This was well before the Wari culture and the later imperial expansion of the Incas. Before being conquered by the Incas in the 14th century, Marcahuamachuco was known as northern Peru's most important political, economic and military center.[1]

Researchers believed that the site as an oracle center, and for religious and political ceremonies. In the later stages of the culture, it was used as a burial site for the elite. Its influence extended through much of northern Peru and contemporary southern Ecuador. This importance may have been related to trade with its neighbors between AD 650 and 700, the Mochica to the west, the Recuay culture to the south, Cajamarca in the north and lesser-known cultures of the Maranon.

Built defensively on top of an isolated highland mesa that is 5 kilometers long and 500 meters wide, with a vast view of the surroundings, Marcahuamachuco contains several major compounds. These were surrounded by curved stone walls as high as 12 meters. The remains of inner galleries, rooms and plazas suggest administrative and ceremonial functions. During the later Middle Period (AD 700 - 900) followed into the Intermediate Late Horizon (until around 1200), archaeological evidence suggests that human burials were made within the walls. These contributed to the ceremonial functions of the site.

Marcahuamachuco probably had oracles, who attracted people from the northern Andes, the areas that today comprise Peru and Ecuador. The cult was probably related to deities, an old cult to Ataujo, and a more recent cult to Catequil. Marcahuamachuco became a prominent center at the same time that the Wari in southern Peru culture flourished (AD 400 – 1100). The site was likely abandoned in the 15th century.

The latest investigations of the site by researchers John and Theresa Lange Topic (1991) suggested that occupation may have been seasonal, with a maximum population of 6,000. Their estimate is based upon the quantity of arable land and water availability.[2]