The definitive closure of the mines of La Unión Historical milestone · La Unión, Campo de Cartagena, Murcia Image of La Unión, not of the place itself. The end of open-pit working put a final stop in 1991 to two millennia of mining in the range, begun by Punics and Romans; the landscape of pits, headframes and washing plants remained as testimony of a vanished economy. 1991 Photo: Nanosanchez (Public domain) What to see and do in La Unión