Mount Gabriel is one of the oldest copper mines in Europe dating back to the end of the Chalcolithic period, around 2500 BC. Most of the mining took place in what we call the Bronze Age now, but that doesn't diminish this site's Chalcolithic importance. They weren't mining for bronze, in part because bronze has to be made by mixing tin and copper at high temperatures. They were looking for copper. And before they figured out how to make the bronze they were busy making copper items, like this flat copper axehead now hosted in National Museum of Ireland. This artifact was found in the soil of a limestone quarry in the County Clare.