Reactivación de las minas de Riotinto en 1725 Historical milestone · Minas de Riotinto, Cuenca Minera, Huelva Image of Minas de Riotinto, not of the place itself. Mining activity, in decline since Antiquity, resumed after 1725, the year in which Swedish engineer Liebert Wolters Vonsiohielm obtained from the Crown the right to work the deposits for a period of thirty years, laying the foundations of modern mining at Riotinto. Photo: Antonio Montilla Lucena (CC BY-SA 3.0) What to see and do in Minas de Riotinto