COLERAINE, seaport and market town, Co. Londonderry, Ireland, on the Bann 4 m. from its mouth. Population of urban district (1926) 8,078. A bridge connects the town with its suburb, Waterside or Killowen, on the opposite bank of the river. The main town on the east bank radiates from a central square —the Diamond. A rath (encampment) occupies Mount Sandel I m. S.E. of the town. There was once a priory, monastery and castle, but no ruins remain. Coleraine owed its importance to the Irish Society, which was incorporated under James I. as the Company for the New Plantation of Ulster in 1613. This society founded and maintained schools in the town. The linen trade is important—a fine cloth being known as "Coleraines." Whisky distilling, pork-curing and fishing are carried on. The harbours were much improved by grants from the Irish Society of London and the River Bann Navigation Act 1879.