Wieliczka Salt Mine, Kraków, Poland

Over the centuries, visitors to this site have included Nicolaus Copernicus, Johann Wolfgang von Goethe, Alexander von Humboldt, Fryderyk Chopin ( 23 July 1829), Dmitri Mendeleyev, Bolesław Prus (1878), Ignacy Paderewski, Robert Baden-Powell, Jacob Bronowski (who filmed segments of The Ascent of Man in the mine), Karol Wojtyła (the later Pope John Paul II), former U.S. President Bill Clinton, and many others. During World War II, the salt mine was used by the occupying Germans as facilities for war-related industries.
To get down to the 64-metre level of the mine, visitors must descend a wooden stairway of 378 steps. After the three-kilometer tour of the mine's corridors, chapels, statues and lake, 135 metres underground, visitors take an elevator back up to the surface. The elevator holds 36 people (nine per car) and takes some 30 seconds to reach the surface (although the wait to board the elevator can be long).
The salt mine helped inspire the Labyrinth scenes in Bolesław Prus' 1895 historical novel, Pharaoh.
In 1978 the Wieliczka salt mine was placed on the original UNESCO list of the World Heritage Sites. In 2010 it was proposed to add Bochnia Salt Mine to the original inscription.