CAIRO – 11 May 2022: The Wieliczka Salt Mine is a 327-meter-deep underground network of artificial tunnels for the extraction of salt, located below the town of Wieliczka in southern Poland.
The history of salt work in Wieliczka dates back to the Neolithic period. The brine was collected from nearby springs and boiled in clay pots. It has been used as a preservative for various types of meat and fish, according to heritagedaily.
By the 11th and 13th centuries, the decrease in salt in the spring water led to the digging of a series of deep wells to extract water with higher amounts of salt. Refined rock salt, a precious mineral composed primarily of sodium chloride, was then discovered, and seasonal mining operations spread to extract valuable rock salt deposits.
By the 14th and 15th centuries the Wieliczka salt was established as a lucrative source of revenue for Casimir III the Great, who used the money generated from the mine to build the Krakow Academy. Mining was increased to an industrial scale during the 16th to 18th centuries. Deep level mines were excavated on a series of levels and brine was evaporated in special furnaces.
The change of borders in Poland in 1772 split Wieliczka's status under the Habsburg monarchy. The new owners invested in building an underground railway, a power station, and a steam lift that converted the Wieliczka mine into a modern brine business. After the end of World War I and Poland's restoration of independence, the mine again became the property of the Polish State Treasury and was taken over under Polish administration.
In the interwar period, salt production reached 203,000 tons per year, but production was halted during the Nazi occupation with the mine being reused as an underground weapons factory.
In 1964, the extraction of rock salt was discontinued completely in favor of the industrial production of evaporated salt using the wet mining method.
The mine is now an official National Historic Landmark in Poland, and in 2010 it was accepted as a UNESCO World Heritage Site along with the Bochnia Salt Mine.