Gorge of los Beyos Nature · Oseja de Sajambre, La Montaña de Riaño, León The gorge or ravine of Los Beyos, carved by the río Sella through the limestone of the Cantabrian range, closes off the municipality of Oseja de Sajambre to the north and marks the natural passage between the Sajambre valley and Asturias. Its name comes from «beyu», a local word for gorges and ravines. It has a total length of about 20 kilometres, of which 11 -between Ceneya and Cobarcil- form the gorge proper, with almost vertical walls through which the river and the N-625 road barely pass; the stretch begins at the site of Covarcil, within the municipal boundary, and extends to the bridge of Angoyo, where the province of Asturias begins. Photo: Tnarik (CC BY-SA 2.0) What to see and do in Oseja de Sajambre