You step off the trail into a narrow green cleft where water has carved its own route through granite and sandstone.
Cold riffles and emerald plunge pools greet you; the guide clicks a harness, points to a smooth rock and invites you to ride a natural slide into the next basin.
The Riera de Osor runs through the Guilleries—an upland of folded rock and dense beech and oak—where centuries of rain have sculpted cliffs, arches, and splash carves that make this canyon an ideal place to learn rope progression and basic canyon technique.
Historically the Guilleries sheltered woodcutters and refugees; today the same steep slopes keep the river shaded and the flow lively through spring melt.
Culturally, nearby villages like Osor preserve stone bridges and small chapels—good stops before or after a trip.
Expect a mix of short jumps, slides, narrow galleries and one or two easy abseils guided by professionals; the route is designed for families and beginners so instruction is part of the experience.
Practical guidance: come ready to swim, wear a secure water shoe, and leave jewelry ashore.
Water temperature will be brisk outside high summer and current can push you through constrictions—listen to guides and scout jumps when offered.
Sessions typically last about three hours including gear fitting and a short safety briefing; operators provide wetsuits, harnesses, helmets and a photo report, but pack a dry set of clothes for the drive back.
Timing your visit for late spring or early fall balances flow and warmth, while mornings often mean fewer groups on the water.