Sant Nicolau Valley Nature · la Vall de Boí, Alta Ribagorça, Lleida The Sant Nicolau valley extends along the left bank of the Noguera de Tor river, within the district of the Vall de Boí, formed by its tributary of the same name, which flows from east to west through the north-eastern part of the Alta Ribagorça. It is reached by a track that leaves from Caldas de Bohí and leads into a narrow gorge, flanked by the Comaltes peak and the Sierra de Martí Llac, with snow-capped summits for much of the year; a good part of the western area of the Aigüestortes national park belongs to this valley. Beside Lake Llebreta, at 1,617 metres, stands the hermitage of San Nicolás, a modern reconstruction of the 12th-century Romanesque building, destroyed by an earthquake. Further east, at Aiguastortas, the river forms a network of channels and islets amid a fir forest. Photo: Josep Borrut (CC BY-SA 3.0) What to see and do in la Vall de Boí