Roman canals of Llamas de Cabrera Monument · Benuza, La Cabrera, León Image of Benuza, not of the place itself. A conditioned stretch of the hydraulic network that supplied the gold mines of Las Médulas: more than six hundred kilometres of channels cut into the hillsides, among them the C3, of 143 kilometres, the second longest water conduit of the ancient world. Photo: Hovallef (CC BY-SA 4.0) What to see and do in Benuza