Uncovered in 1987, the Great Orme copper mines in Llandudno currently hold the Guiness world record for largest Bronze Age copper mines in the world. 70% is still yet to be explored but there's a visitor's centre on top of the Orme with a self-guided tour of the the first 2 levels of the mine.
You can find out more about the mines on the Great Orme copper mines website.
