Those parts of Northumberland, Tyne and Wear and Durham bounded by:

On the North by the border with Scotland. On the South by a straight-line westwards from the sea to the junction of the A1086 / B1281 junction. B1281, A181 to Durham, A690 (via Willington and Crook), A689 (via Stanhope) to St. John's Chapel to Cumbria boundary at Killhope Moor. On the West by the boundary between Cumbria and Northumberland.