Ser River Nature · Cervantes, Ancares, Lugo Image of Cervantes, not of the place itself. The río Ser rises at almost 1,800 metres above sea level on the western slopes of the sierra de los Ancares, at the confluence of the Moreira and Mazo streams, near the village of Piornedo. It runs through the northern part of the municipal district of Cervantes, separating the hamlets of Castelo and Donís, before entering Navia de Suarna and flowing into the río Navia after a course of 23.1 kilometres, through woods of alder, ash and oak that hide its bed within a canyon. Its basin, covering 114 square kilometres, is included in the Cruzul-Agüeira Site of Community Importance and in the Os Ancares Lucenses y Montes de Cervantes, Navia y Becerreá Biosphere Reserve, of which the municipality of Cervantes has been part since 2006. Photo: SanchoPanzaXXI (CC BY-SA 3.0) What to see and do in Cervantes