The former galena (lead ore) and blende (zinc ore) mine illustrates the evolution of a mountain mine operation between the Middle Ages and the 19th century. The configuration of the various galleries successively opened testifies to each era of exploitation. This very mineral industrial site on a slope covered with mining cuttings contrasts with its alpine and forest environment. Some buildings still have their 19th century stone facades.
The mine has about fifteen kilometers of galleries, including four main galleries: the Saracen Gallery (the oldest), the gallery Ste Barbe (540 m long), the Charles-Emmanuel Gallery (780 m long, Negri Gallery – the most recent of 1,170 m), and four intermediate galleries that do not open to the day.
The different levels of the mine are joined together by a system of interior declining tunnels and chimneys.