The area of the Metalliferous Hills, characterized by forests, woodsand densescrub, is located north of the Piana di Grosseto, in a vast area rich, since ancient times, of mineral deposits of iron, copper, lead and silver. At present they are disused or abandoned (the main ones are located in Campiglia Marittima, Gavorrano, Massa Marittima, Montieri and Boccheggiano), but traces of the past still remain: from the Etruscan tunnels to the landfills of sterile material of medieval times up to the high contemporary metal structures, classified as testimonies of industrial archeology. Mining is also linked to the abundance of vegetation, therefore, of timber, which is essential both to arm the tunnels of the mines and to feed the furnaces for the melting of metals. As a demonstration of the importance and uniqueness of the area in 2010, the Park of the Metalliferous Hills was included in the Network of European Geoparks (European and Global Geoparks Network) under the name of Tuscan Mining Geopark (Geoparco delle Colline Metallifere),obtaining the prestigious recognition from UNESCO.
The Metalliferous Hills of the Tuscan Maremma (Livornese and Grossetana) include the municipal territories of Sassetta, Campiglia Marittima, Suvereto, Gavorrano, Massa Marittima,Monterotondo Marittimo, Montieri, Roccastrada, Scarlino and the northern part of the municipality of Castiglione della Pescaia. Also part of it, due to the identical geological characteristics, is the hill massif of Poggio Ballone,and therefore the entire pedecollinare area that, divided by the remaining hilly territory by the Pecora river, opens to the Gulf of Follonica.