FERMANAGH, a county of Ireland, in the province of Ulster, bounded north-west by Donegal, north-east by Tyrone, east by Monaghan, and south to west by Cavan and Leitrim. The area is 417,912 ac., or about 653 sq. miles. The county lies chiefly in the basin of the Erne, which divides it into two nearly equal sections. The surface is hilly and, especially round Lough Erne, is picturesque. The climate, though moist, is healthy. The chief mountains are Cuilcagh (2,188 ft.) and Tiltinbane (1,949) , partly in Leitrim and Cavan; Belmore (1,312) , west of Enniskillen; Glenkeel (1,223) ; Shean North (1,13 5) , rising from Lough Erne; Tappaghan (1,122) in the north; Dooharn (1,255) and Carn more (I,o34) on the east of the loughs. Tossett or Toppid and Turaw (Tooraw) mountains on the west form striking features in the scenery. But the most distinguishing features are the Upper and Lower Loughs Erne, stretching from south-east to north-west. These lakes are expansions of the river Erne, which enters the county from Cavan, flows through Upper Lough Erne, past Enniskillen and through Lower Lough Erne, on its way to the Atlantic at Ballyshannon. At Belleek it forms a considerable waterfall, and is here notable for good salmon fishing. Trout are taken in most of the loughs, and pike of great size in the Loughs Erne. The western boundary takes in a small portion of Lough Melvin, and Upper and Lower Loughs Macnean (or Lough Nilly) lie on the Cavan border. Various streams feed the two principal loughs. There are chalybeate and sulphur springs. At Belcoo, near Enniskillen, there is a well in local repute for its cure of paralytic and other diseases ; and 4 m. N.W., at a place called "the Daughton," are natural caves.
This county includes in the north an area of gneiss from Donegal and a metamorphic region from Tyrone. A fault divides the latter from the Old Red Sandstone that spreads south. Lime stone forms fine scarps on the south side of Lower Lough Erne, capped by beds regarded as the Yoredale series. The scenery about Loughs Macnean rises in similarly scarped hills to the summit of Cuilcagh. The "Marble Arch" cave near Florence court, with its emerging river, is a characteristic subterranean waterway in the limestone. Higher Carboniferous strata form highlands north-east and south-west of Upper Lough Erne.
Fermanagh is chiefly a pastoral and agricultural county. There are pottery works at Belleek. Three branches of the G.N. rail way—from Clones, from Londonderry via Omagh, and from Bundoran—meet at Enniskillen. The Sligo, Leitrim and North ern Counties railway, connecting with the southern and western systems, also runs to Enniskillen, and the Clogher Valley light railway connects with the G.N. railway at Maguiresbridge.