Even further afield, there were extensive copper and gold mines, for export, in very early Ireland, also proto-Celtic times.<p>Per Wikipedia re: mines in Cork and Kerry: &quot;mining and metalworking took place there between 2400 and 1800 BC. ... Mines in Cork and Kerry are believed to have produced as much as 370 tonnes of copper during the Bronze Age. As only about 0.2% of this can be accounted for in excavated bronze artefacts, it is surmised that Ireland was a major exporter of copper during this period.&quot;