Cascada Aiguallut is a superb waterfall fed by the glacier Aneto. From Hospital de Benasque (Valle de Benasque) it is a 90 min walk, alt difference of 280 meters.
Nearby is the Forau de Aiguallut, which means deep hole. Here the water disappears underground. It was long time a miracle where the water stayed, but 4 km further, 600 meters lower, the water appears again on the other side of the mountain: In France, in the Val d’Arân.