Visit the real world of wonders the wieliczka salt mine was inscribed onto the first unesco world natural and cultural heritage list it reaches a depth of 327 meters and the mine passage is almost 300 km long the salt mine continuously produced kitchen salt from the 13th century until 1996 being one of the worlds oldest operating salt mines it isundoubtedly one of the most frequently visited sites in poland there are no appropriate words to express the mystery and beauty of the wieliczka