The Tellure mining park in Sainte-Marie-aux-Mines has a via ferrata, installed within underground galleries dug in the Middle Ages and the Renaissance. The course combines climbing and caving of varying degrees of difficulty. It gets as close as possible to the ore veins exploited in the 16th century. Traces of silver, copper, lead, and crystal still emerge from the gneiss walls. The region abounds in minerals, and every year five days are devoted to one of the largest gatherings dedicated to gems and minerals in the world, in Sainte-Marie-aux-Mines.