Dique de Campofrío Monument · Campofrío, Cuenca Minera, Huelva Dam built in 1883 to serve the area's mining operations, raised higher between 1940 and 1950 to meet increased production; it forms part of the municipality's industrial heritage. Photo: Marc Ryckaert (MJJR) (CC BY 3.0) What to see and do in Campofrío