Leitrim is a county in the Irish province of Connaught and it is bounded on the north by Donegal Bay. Here is has a coastline of 2.5 miles. It is also bounded on the north by Counties Donegal and Fermanagh, on the east by Fermanagh and County Cavan and on the south by County Longford. Lough Allen divides County Leitrim into two parts.