Corta y nacimiento del río Tinto en Peña de Hierro Nature · Nerva, Cuenca Minera, Huelva Beside the old Peña de Hierro opencast mine rises the río Tinto, its waters reddened by iron mineralisation, within the Río Tinto Protected Landscape. Photo: David Sánchez Núñez (CC BY-SA 3.0) What to see and do in Nerva