Mining has played an important role in the history of the Valles del Oso region, (Proaza, Quirós, Santo Adriano and Teverga).

The mining of its rich deposits needed railway lines to carry away the output of the mines. Then the mining crisis shut down the mines and the railways.

However, the railways have in some way been given a new lease of life thanks to their recovery as a Greenway, the Senda del Oso Greenway (literally the Bear Trail Greenway), which offers us a journey through the essence of Asturias at its most natural and rustically charming.