The gorges of the Pinu are a short gorge ( gorges is, in Asturian, 'sickles') pierced by the Pino river forming numerous rapids and waterfalls near the village of Pino in the council Asturian of Aller . The environment was declared a natural monument on April 19 , 2001 and protects an area of 76 hectares. The small 6-kilometer river forms numerous rapids and waterfalls, although the stretch of the gorge itself consists of only 300 m of almost vertical walls with a width that, in some cases, does not exceed 6 m.
In the vegetation you can distinguish several areas:
- from the beginning to the sickles, high mountain pastures and heaths with holly abound. The predominant trees in this area are beech trees ;
- the sickles with little vegetation due to the abrupt terrain with some yew ;
- intermediate zone, behind the sickles, with an extensive beech forest and the rest of pastureland with hazelnuts and some sessile oak ;
- the final part, before the mouth of the San Isidro river , in which there are many meadows for cultivation and chestnut trees . On the bank are willows and alders ;
This group of peaks, the Serranía de las Fuentes de Invierno, had already been classified as outstanding landscape, in the inventory carried out in 1978 by ICONA.