Swansea (Welsh: Abertawe), officially known as the City and County of Swansea (Dinas a Sir Abertawe), is a coastal city and county in Wales. It is the second largest city in Wales after Cardiff, and the twenty-fifth largest city in the UK. Swansea lies within the historic county boundaries of Glamorgan and the ancient Welsh commote of Gŵyr. Situated on the sandy South West Wales coast, the county area includes the Gower Peninsula and the Lliw uplands. During its 19th-century industrial heyday, Swansea was a key centre of the copper industry, earning the nickname ‘Copperopolis’. Since 2011, Swansea has started to expand into a larger region known as the Swansea Bay City Region.
Swansea is thought to have developed as a Viking trading post. Its English name may be derived from Sveinn’s island (Old Norse: Sveinsey) – the reference to an island may refer to a bank at the mouth of the river Tawe, or an area of raised ground in marshes. An alternative explanation is that the name derives from the Norse name ‘Sweyn’ and ‘ey’, which can mean inlet. This explanation supports the tradition that the city was founded by the Danish king Sweyn Forkbeard. The name is pronounced Swans-y /ˈswɒnzi/), not Swan-sea.