The salt mine in Wieliczka and the salt mine in Bochnia are parts of so-called żupy krakowskie. The rock salt extracted in mines comes from the Miocene. The salt mine in Wieliczka was inscribed on the UNESCO World Heritage List in 1978. The salt mine in Wieliczka was acknowledge as one of the seven wonders in Poland in the plebiscite of “Rzeczpospolita” newspaper in 2007.