The work and patience that must have gone into the creation of these sculptures is extraordinary. One wonders what the miners would have thought of their work going on general display. They came to be quite used to it, in fact, even during the mines busiest period in the nineteenth century. The cream of Europe's thinkers visited the site -- including Nicolaus Copernicus, Johann Wolfgang von Goethe, Alexander von Humboldt, Dmitri Mendeleyev, Bolesław Prus, Ignacy Paderewski, Robert Baden-Powell, and Karol Wojtyła, who later became Pope John Paul II. During World War II, the salt mine was used by the occupying Germans as facilities for war-related production plants.