Its rapid growth was fuelled by the iron industry and coalmining, and when they came to an end, they left behind a remarkably complete industrial town.
Ysgogwyd y twf cyflym hwn gan y diwydiant haearn a gweithgarwch glofaol a phan ddaeth y rhain i ben, gadawyd tref ddiwydiannol ryfeddol o gyflawn ar eu hôl.