It's a beautiful climb, very typical of this area of Asturias. It's wild, authentic, and very tough, like any secondary road in the municipality of Cangas del Narcea. There are many like this one, not only in the Narcea Valley but also in the nearby Naviego and Coto River valleys.
The first stretch to the village of Sierra de Castaneu is easy, with some steep but uneven gradients. It's 3.5 km in total. The main drawback of this section is the condition of the asphalt, very uneven and full of potholes. The road is wide and has sufficient visibility for the light traffic.
The second stretch is 3 km with no breaks, starting from the village of Sierra de Castaneu. The road narrows, but the surface improves significantly, completely unexpectedly. The trees disappear, and the views of the Narcea Valley are wonderful, allowing you to enjoy the tranquility of the place.