The River Dargle is a river that rises in the Wicklow Mountains, Ireland on the southern slopes of Tonduff 642 metres . It flows down the Glensoulan hanging valley, to fall over the 121 metres Powerscourt Waterfall. The Dargle then flows through the Glencree valley where it is fed by the River Glencree, before flowing east for a further 13 km where a small tributary the Swan River joins opposite the People's Park, Little Bray. The final section 1 km section reaches the Irish Sea at Bray Harbour. The river's name in Irish refers to the tint of red in the rocks at its source.