Caudal River Nature · Mieres, Caudal, Asturias The Caudal river rises at Sovilla, in the concejo de Mieres, at an altitude of 256 metres, from the confluence of the Lena and Aller rivers, and runs 20.6 kilometres northward, passing through Ujo, Santullano, Mieres, Santa Eulalia, Argame and Figaredo, before flowing into the Nalón river at Soto de Ribera. It gives its name to the whole comarca and was one of the two great mining basins of Asturias, with its floodplain concentrating the coal pits, washeries and workers' settlements. During the revolutionary strike of the summer of 1917, the so-called Tren de la Muerte ran through its valley, from which soldiers fired in reprisal against the population. Mallards, cormorants and grey herons are often seen in its waters. Photo: Montes (Public domain) What to see and do in Mieres