Tellure Park is built above a network of mining galleries, some dating from the Middle Ages. The via ferrata established in 2009 allows a deep immersion into the Saint-Jean silver vein, discovered in 1549. The walls of its galleries still bear traces of the blows of the chisels. Buckets, winches, and small wagons called mine dogs were used to raise the ore to the surface. The trolleys circulated on slightly spaced planks enclosed by a stop for guidance.