Mines of Horcajo Curiosity · Almodóvar del Campo, Valle de Alcudia, Ciudad Real Former argentiferous lead mining district, discovered in 1858 in a small Y-shaped valley of the sierra Madrona, near the boundary with the province of Córdoba, which came to house its own settlement of some 4,500 inhabitants and was one of the most productive in Spain in the late 19th century, with output reaching 13,423 tonnes a year after mechanical drilling began in 1882. The operation, which at its peak employed hundreds of men and pack animals to transport the ore, went into decline as the vein became depleted, until the Sociedad Minero-Metalúrgica Peñarroya halted it in 1911; a narrow-gauge mining railway continued in service until 1970. Today only industrial ruins and spoil heaps remain, in the heart of the Valle de Alcudia. Photo: Miguel Calvo (CC BY-SA 4.0) What to see and do in Almodóvar del Campo