In Sainte-Marie-aux-Mines in the Haut-Rhin department, the Tellure Mining Park is built on the very site where numerous silver veins were discovered in the 16th century. The poor and isolated valley of the Liepvre river experienced then a “silver fever”, which attracted thousands of miners from Saxony and Bohemia. The Saint-Jean Engelsbourg silver mine is the largest man-made underground cavity in the Vosges mountains. Equipped with cables, steps and ladders, most of which date back to the 16th and 18th centuries, this underground via ferrata allows speleological visits supervised by qualified speleological guides.