krakow, poland wieliczka salt mine - kopalnia soli wielicska - illuminated interior top view, with wooden ladder leading to the

krakow poland wieliczka salt kopalnia soli wielicska interior wooden ladder underground chamber cave old rock polish tunnel history museum structure heritage historical wood depth architecture tourism travel landmark indoors geology destinations attraction people tourist unesco world site stone material tunneling culture beaten path international kopalna mining natural resources symbol wall illuminated top view leading scenic route route