The River Blackwater or Ulster Blackwater is a river in County Armagh and County Tyrone, Northern Ireland, that partly flows through County Monaghan, Republic of Ireland, which has its source to the north of Fivemiletown, County Tyrone.
The River Blackwater or Ulster Blackwater is a river in County Armagh. The River Blackwater or Ulster Blackwater is a river in County Tyrone. County Tyrone is Northern Ireland. County Tyrone partly flows through County Monaghan. County Monaghan is Republic of Ireland. County Tyrone is Northern Ireland. County Monaghan has its source to the north of Fivemiletown, County Tyrone. County Monaghan is Republic of Ireland.