The fortress of Kuelap or Cuélap (Chachapoyas, Amazonas, Perú), associated with the Chachapoyas culture, consists of a walled city, with massive exterior stone walls surrounding more than four hundred buildings. The complex, situated on a ridge overlooking the Utcubamba Valley in northern Peru, is roughly 600 meters in length and 110 meters in width. It could have been built to defend against the Huari or other hostile peoples. However, evidence of these hostile groups at the site is minimal. Radiocarbon dating samples show that construction of the structures started in the 6th century AD and the complex was occupied until the Early Colonial period (1532-1570). Through the pre-Columbian, conquest and colonial periods, there are only four brief written references to Kuelap.