The fortress of Kuelap or Cuélap (Chachapoyas, Amazonas, Peru), is a walled city associated with the Chachapoyas culture built in 6th century AD. It consists of more than four hundred buildings surrounded by massive exterior stone walls. The complex is situated on a ridge overlooking the Utcubamba Valley in northern Peru and roughly 600 metres long and 110 metres wide. It could have been built to defend against the Huari or others, but evidence of hostile groups at the site is minimal.
The monumental ruins of Kuelap are situated at 3000 metres above sea level. The ruins of Kuelap are located at the summit of a hill that rises on the left bank of the Utcubamba, at coordinates 6°25′07″ S 77°55′24″ W, according to the engineer Hernán Corbera. Access to Kuelap is gained via El Tingo, a town at approximately 1800m above sea level, near the bank of the Utcubamba. A horse trail also winds along the left bank of Tingo river and leads eventually up to Marcapampa, a small level upland near the site.
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.
It was rediscovered in 1843, when Juan Crisóstomo Nieto, a judge in Chachapoyas, made a survey of the area and took note of Kuelap's great size; he was guided by villagers who had known of the site for generations. Subsequently, Kuelap gained the attention of explorers, historians and archaeologists. Notable observers who helped publicize the site included Frenchman Louis Langlois who wrote a description of Kuelap in the 1930s, Adolph Francis Alphonse Bandelier, Ernst Middendorf, Charles Wiener and Antonio Raimondi.