From an article published on the BBC News web site on 29th July 2005:
Archaeologists have uncovered the remains of a Roman lead smelting site in a peat bog in Ceredigion.
Dating back about 2,000 years, Cambria Archaeology said mines in the Borth area could have supplied the heavy, bluish-grey metal for production.
Someone should really point out to this lot that 2000 years ago the Romans hadn’t got to Wales. Even taking the inaccuracies of carbon dating into account, it seems likely that the lead smelting was being carried out by the indigenous Celts rather than Romans.