The copper hammer mills Curiosity · Navafría, Comunidad de Villa y Tierra de Pedraza, Segovia Image of Navafría, not of the place itself. On the banks of the river worked martinetes, water-driven hammers that beat copper to make cauldrons and utensils; one of them is preserved and has become an anthropological museum of the trade. Photo: jacinta lluch valero from madrid * barcelona...., (España-Spain) (CC BY-SA 2.0) What to see and do in Navafría