Ruta del Cares

The Cares Route (PR-PNPE 3) runs through the Picos de Europa National Park, between León and Asturias. The Poncebos–Caín stretch is 12 km long (21 km if you start from Posada de Valdeón) and takes 6–8 hours there and back; Poncebos is at 260 metres of altitude and the cumulative climb to Caín is +450 m.

The path runs through a gorge carved in grey limestone, with almost vertical walls. You can see chamois, goats, roe deer, foxes, griffon vultures and golden eagles; vegetation is sparse and in summer the terrain is dry and hot.

The canal, with 71 tunnels, was dug between 1915 and 1921 for the Poncebos power station, and 11 workers died during the work. The path was upgraded between 1945 and 1950 and reopened in 2012, after a rockfall in 2011.

Source of the information: Ruta del Cares (Wikipedia)