Formation of the Salt DepositThe salt in the Wieliczka mines is older than modern humans. During the Miocene era, 13.6 million years ago, the plates of the earth in central Europe shifted to create new mountain ranges, including the Carpathians. Salty seawater pooled in the depression in front of the Carpathians, which left salt deposits behind as the region developed, leaving layers of rock salt buried between 30 and 330 meters underground. The salt mined in the Wieliczka and Bochnia mines was extremely pure and was sold as Eagle Salt, in barrels featuring the white eagle of Poland.
History of Salt MiningThe Wieliczka salt mines are some of the oldest in Europe, with rock salt being discovered there in the 13th century. The mines received their charter from King Casimir III the Great in 1368, which laid down the rights of the miners and the laws that regulated the production and trade of salt. In the 15th century, approximately 350 people worked in the mines, producing up to 8,000 tonnes of salt per year. In the 16th and 17th centuries, the Wieliczka and Bochnia Royal Salt Mines (as they came to be known) flourished as the largest mining company in Poland. From 1772, the region was ruled by Austria, and the mines were extremely important for the economy of the large and powerful empire. Tourism was recorded in the mines as early as 1774, with the oldest tourist route through the mines dating back to the 19th century - it soon became another source of income for the company, in addition to the sale of their products. Commercial mining ended in 1964 after nearly 700 years of operation as a result of the rising costs and the new competition from sea salt, which meant that running the mine became economically unviable.