On a recent visit to Anglesey (North Wales) we spent a few happy hours exploring Parys Mountain, which is a really beautiful place. It's so colourful, which comes from the copper within it - it was once the main copper supplier for the world. (see website extract below).
"Parys Mountain is a special place, which has fascinated visitors for hundreds of years. Recent discoveries are pushing back the frontiers of knowledge of its early occupants as more evidence for early bronze age working of the mine is identified.
"The rocks of Parys Mountain originated as muds in the margins of a sea basin around 440 million years ago.
"This copper dominated the world's markets in the 1780s. It was used to sheath the admiralty's wooden ships of war, in order to prevent the growth of seaweed and barnacles and to prevent boring by worms."