Yaynu, Archaeological site in Huayllán District, Pomabamba Province, Peru

Yaynu is an archaeological site with high stone walls and building remains spread across a mountain ridge in Ancash at 4,000 meters elevation. The structures fit into the steep terrain and form a complex settlement layout that once housed multiple functions.

Yaynu was built progressively between cal. AD 400 and 800 by groups of the Recuay tradition, and its main occupation belongs to that span. It stood at the centre of a network linking small nearby farming villages. Its perimeter walls, reported as reaching 15 m in their day, long trenches and restricted accesses protected the community and kept internal groups physically segregated. Inca-period offerings have been found at the site.

The site displays pottery and tools that show how people of the Recuay period worked and lived on this mountain. These objects reveal the skills and knowledge that shaped daily life in this highland community.

Access starts from Pomabamba, about 17 km north of the site; the ruins lie above 4,000 m on the northern slope of Pañahirka, near the Yaynohirka hill. The altitude and mountain weather demand prior acclimatization, water, sturdy shoes and warm clothing. The perimeter walls, long trenches and restricted entrances make walking uneven.

Yaynu's defensive system combined natural trenches with walls that, according to the Spanish source, may once have reached 15 metres in height. Offerings from the Inca period were also found at the site, showing it was visited long after its Recuay occupation ended.