Gorges of El Pino Nature · Aller, Caudal, Asturias Image of Aller, not of the place itself. A narrow gorge some three hundred metres long cut by the River Pino through the limestone of Peña Redonda, with almost vertical walls that at some points narrow to six metres; a natural monument since 2001 covering 76 hectares. Photo: SITOMON (CC BY-SA 4.0) What to see and do in Aller