The Paiva River is fast-moving, cold, and exceptionally clear — one of the least polluted rivers in Portugal. Several operators based near Arouca offer guided kayak and canoe trips along sections of the river, ranging from easy half-day floats suitable for families to more technical runs through the gorge. The season runs roughly from April to October, with the river at its most dramatic in spring when snowmelt from the Serra da Freita keeps the water level high.
Wild swimming is possible at several points along the Passadiços do Paiva trail and at the river beach near Espiunca. The water temperature rarely exceeds 18°C even in summer — it is refreshing rather than warm. Local operators can also arrange multi-day canoe descents with camping overnight on the riverbanks. Book in advance through the Arouca tourism office or through one of the adventure sports companies based near the trailheads.