Barrow, River, rises in the Slieve Bloom Mountains in the province of Leinster in the Republic of Ireland. It flows for 119 miles (192 kilometers) through the counties of Laois, Offaly, Kildare, and Carlow. The River Barrow is joined by the Rivers Nore and Suir. The three rivers form an estuary (a deep, broad mouth) at Waterford.
