Oscuros del Balced is the median section of the 22km long Canyon del Balced of the Rio isuala. This exciting canyoneering trip is located 8km south of the hamlet of Rodellar in the heart of Sierra and Canyons de Guara Natural Park in upper Aragon Province of Spain. The trip begins by passing through a huge chaos of blocks which obstruct the river into a narrow passage. It is necessary to use a rope inside the "chaos". This beautiful part is followed by an incredible long aquatic corridor with two small waterfalls (6 meters maximum). Of course, do not enter in this "subterranean" slot if the river in on flood stage. The author especially loves this slot canyon.