Londonderry (county, Northern Ireland), also Derry, former county, Ulster Province, north Northern Ireland; Londonderry was the county town. Londonderry comprised an area that included the Sperrin Mountains in the south and a coastal plateau on Lough Foyle and the Atlantic Ocean in the north. The region has many sites that indicate occupation by prehistoric people. It was taken by the English in 1609; Protestant emigrants from Scotland and England settled here, and in 1613 the county was granted a charter. County Londonderry ceased to exist as an administrative unit in 1973.
The main towns in Londonderry include Londonderry, Coleraine, Limavady, Dungiven, Maghera and Magherafelt. The capital is Londonderry (city).