The building housing Tellure Park is built on the same underground site where numerous silver veins were discovered in the 14th century causing the Silver fever. The Saint-Jean Engelsbourg silver mine known as La Colonne Saint-Jean is the largest man-made underground cavity in the Vosges Mountains, a particularly breathtaking cavity (180m3). The mine will close definitively in 1976 but in 2009 the Vosges will be keen to help people discover this incredible maze. Laid out like a caving route, the Via Ferrata was born.