Colline Metallifere

The Colline Metallifere (Italian: [kolˈliːne metalˈliːfere]), or the Metalliferous Hills ("Metal-bearing Hills"), are a mountain-hill group in the Tuscan Antiapennine, in central Italy.

They occupy the central-western part of Tuscany, divided between the provinces of Livorno, Pisa, Siena and Grosseto.

It also includes geothermic energy sources, part of which used in ENEL power plants at Larderello and Lago Boracifero.

The metal resources of the Colline Metallifere were exploited since ancient times by the Etruscans.

Production reached its peak in the mid-19th century, declining quickly however afterwards.