BANN, the largest river in Northern Ireland. Rising in the Mourne mountains in the south of Co. Down it runs north-west to Lough Neagh (q.v.), which it drains north-north-west to an estuary at Coleraine, forming Lough Beg immediately below the larger lough. The length of its valley is about 90 miles. The total drainage area of the system is about 2,3oosq.m., extending west ward to Co. Fermanagh, and including parts of the Cos. Down and Antrim, Armagh and Monaghan, Tyrone and Londonderry. The river has valuable salmon fisheries. Above Lough Neagh it is known as the Upper Bann and below as the Lower Bann.