The history of the valleys of the Oso (Proaza, Quirós, Santo Adriano, and Teverga) have been marked by mining. 

The mining of their rich deposits led to railway lines that provided an outlet for their production. The mining crisis closed down mines and railways.

The latter have been relived to a certain extent thanks to their use as a Greenway: the Senda del Oso, which invites us on a journey through the essence of the most natural Asturias and the rustic singularity of places full of authenticity.
 

Basic Facts
	Entrago - Trubia passing through Caranga de Abajo and Proaza. Valdemurio branch: Caranga de Abajo - Santa Marina. Asturias
	Trekkers, cyclists, suitable for people with reduced mobility
	Note: Suitable with very few limitations. (Curbs at road junctions without a hard shoulder)
	Asphalt (cement)
	Fuso Greenway by way of the Nalón River Nature Trail, the Cantabrian Mountains Nature Trail and the Nature Trails towards Riocabo and Huerta Cave
	Numerous tunnels, bridges and footbridges
	43.169254, -6.097268
	43.345847, -5.969471