metropolitan borough, metropolitan county of Tyne and Wear, northeastern England. It lies just southeast of the city of Newcastle upon Tyne and is bordered by the River Tyne to the north and the North Sea to the east. South Tyneside's towns— South Shields, Jarrow, Hebburn, and Boldon—have played a prominent role in the industrial development of the Tyne and Wear (or Tyneside) metropolitan area. Light industries were established after World War II in an attempt to mitigate the area's reliance on heavy industries such as shipbuilding and repairing, coal mining, and iron and steel production. While ship repair continues in Jarrow, coal mining has ceased, and heavy industry has nearly disappeared. The borough's economy now depends mainly on service activities and light industry. Stretches of scenic grassland and beach are found along the North Sea coast south of South Shields, the administrative centre, at the mouth of the Tyne. A metro rapid-transit system connects South Shields and Jarrow with Newcastle upon Tyne and North Tyneside. Area 25 square miles (64 square km). Pop. (2004 est.) 151,500.