Northumberland is a county in the north east of England. It is predominantly rural, although the south-east of the county contains several former coal mining towns and villages. The county town is Morpeth; other important towns include Berwick upon Tweed, Alnwick, Hexham and Haltwhistle. Hadrian's Wall crosses the southern part of Northumberland; other major historic sites in the county include the island of Lindisfarne or Holy Island, and medieval fortresses at Bamburgh, Norham, Dunstanburgh, Alnwick, Warkworth and elsewhere. In Berwick, Northumberland has England's only sixteenth century walled town. The traditional county of Northumberland also included areas of Tyneside north of the River Tyne including the city of Newcastle (which, however, was made an independent county as early as 1400) and North Tyneside. These two districts became part of the administrative and ceremonial county of Tyne and Wear in 1974.