Seeing up close the rock so painstakingly dug by the miners is a truly unique experience. The gneiss still contains traces of silver, the mineral that brought the first experienced miners from Saxony and Bohemia in the 16th century. Today, visitors to the Tellure Mining Park in Sainte-Marie-aux-Mines can walk through the miles of galleries with a constant temperature of 10°C. The more experienced can descend to the bottom of the 20-metre-deep shafts using harnesses and ropes. The Saint-Jean Engelsbourg/Tellure silver mine was the largest in the Neuenberg massif (Haut-Rhin).