Down, district (1991 pop. 57,050), 246 sq mi (637 sq km), SE Northern Ireland. The principal town is Downpatrick. The shoreline extends along the Irish Sea and is deeply indented by Strangford Lough. The undulating surface rises to the beautiful Mourne Mts. in the south. Chief rivers are the Lagan and the Bann. Agriculture is the most important activity, and the area is extensively cultivated (oats, barley, wheat, and hay). Market gardening is common in the north. Sheep and pigs are also raised. Manufactures include linen, cotton, rayon, clothing, agricultural machinery, and metals. The chief manufacturing towns are Downpatrick and Ballynahinch. Fishing is economically important; herring and whitefish constitute the main catch. Newcastle and Killyleagh are seaside resort towns.