River Bann (Irish: An Bhanna) is a river in County Wexford, in the southeast of Ireland. It rises in the southern slopes of Croghan Mountain in North Wexford on the County Wicklow border. It flows south and is joined by the Blackwater Stream near the village of Hollyfort. Veering southwest it passes under the R725, then continuing southwestwards it flows beneath the N11national primary route at the village of Camolin. It is crossed by the Dublin - Wexford railway four times as it flows past the town of Ferns before joining the River Slaney north of Enniscorthy. In 1950s a reservoir was built at Ballythomas to supply water to the town of Gorey, Co Wexford. Before that its banks regularly spilled over and made a lot of swamp land on its route.