Interesting question - it seems like there were Welsh mines in Roman times: https://en.wikipedia.org/wiki/Dolaucothi_Gold_Mines https://en.wikipedia.org/wiki/D

Interesting question - it seems like there were Welsh mines in Roman times: https://en.wikipedia.org/wiki/Dolaucothi_Gold_Mines https://en.wikipedia.org/wiki/Dolaucothi_Gold_Mines > They are the only mines for Welsh gold outside those of the Dolgellau gold-belt, and are a Scheduled Ancient Monument. They are also the only known Roman gold mines in Britain, although it does not exclude the likelihood that they exploited other known sources in Devon in South West England, north Wales, Scotland and elsewhere.