town, Coleraine district, northern Northern Ireland, lying at the northwestern end of the Antrim Coast Road, on the basaltic peninsula of Ramore Head. Offshore in the Atlantic Ocean are the Skerries, a rocky group of islets forming a natural breakwater. The headland, or rocky projectory, called the Giant's Causeway is 7 miles (11 km) east along the coast beyond the White Rocks cliffs and caves. Nearby is Dunluce Castle (14th century), situated on a rock separated from the mainland by a chasm, which is spanned by a footbridge. Portrush has been an important tourist centre, and there is commercial fishing offshore. It is the seaport for the city of Coleraine to the immediate south. Pop. (2001) 6,372.