Northern Ireland occupies the northeastern part of the island of Ireland and consists of six counties: Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone. Belfast, at the mouth of the River Lagan, grew as a port and shipbuilding centre; Harland and Wolff there constructed the RMS Titanic. Lough Neagh sits near the geographic centre and covers about 388 km², supplying a large share of the region’s freshwater supplies.
The north and east coasts meet the North Channel and the Irish Sea, where the Giant’s Causeway displays hexagonal basalt columns formed by cooling lava. Inland are drumlin fields, peat bogs and the lakelands of Fermanagh; the River Bann runs roughly north–south as the longest river wholly within Northern Ireland. Transport routes link towns, ports and rural districts across the region.
