The county traditionally extends to the south bank of the River Tyne and includes Sunderland, South Shields, and Gateshead. It borders the counties of Cumberland, Northumberland, Westmorland and Yorkshire. The east of the county between the Ryhope district of Sunderland and Seaton Carew in Hartlepool is the coastline of the North Sea. Several exclaves have existed in the county's history, including Bedlingtonshire, Norhamshire, Islandshire (incorporated into Northumberland in 1844), and Crayke, now in North Yorkshire. Startforth Rural District is traditionally part of the North Riding of Yorkshire. The modern unitary authorities of Hartlepool, Darlington, and Stockton-on-Tees are part of the traditional County Durham.
