World Cultural Heritage Introduction: Wieliczka Salt Mine has been mining salt since the 13th century. It was at its peak in the 15th and 16th centuries. In the 18th and 19th centuries, the salt mine began to expand and became the famous salt capital of Poland. In 1978, the salt mine was listed as a World Heritage Site. In 1996, the salt mine ceased production and the salt layer was almost exhausted.