Coleraine, Irish Cúil Raithin, town, seat, and district (established 1973; formerly astride Counties Antrim and Londonderry), Northern Ireland. Coleraine town is located near the mouth of the River Bann. Flint implements dating back to nearly 7000 bc have been found in the vicinity; they provide the earliest evidence of human occupation in Ireland. The main town on the east bank radiates from a central square, The Diamond. Modern Coleraine (from the Irish, meaning “ferry corner”) owes its foundation to the companies of the City of London who undertook the colonization of County Londonderry in the 17th century under the scheme for the Plantation of Ulster. A road and rail junction and the seat of the New University of Ulster (founded 1965), the town manufactures Acrilan synthetic fibre and has agricultural processing, a salmon fishery, and light engineering industries. Its harbour accommodates small vessels.
Coleraine district is bordered by the districts of Limavady to the west, Magherafelt to the south, Ballymoney and Moyle to the east, and by the Atlantic Ocean to the north. Western Coleraine is composed of wooded, hilly terrain that slopes eastward to the River Bann valley. Eastern Coleraine is rich agricultural country, producing barley, poultry, and livestock (pigs and sheep). Portrush and Portstewart, located on the Atlantic coast northeast of the mouth of the Bann, are popular resort towns with a line of reefs known as The Skerries directly offshore. Area district, 189 square miles (490 square km). Pop. (2001) town, 24,089; district, 56,315.