"The historic Salt Mine in Wieliczka is the only mining site in the world functioning continuously since the Middle Ages. Its original excavations (longitudinals, traverses, chambers, lakes, as well as minor and major shafts) are located on nine levels and extend for the total of about 300 kilometres: reaching the depth of 327 metres they illustrate all the stages of mining technology development over time."

The quotation comes from the justification for entering the Wieliczka Salt Mine on UNESCO's First World List of Cultural and Natural Heritage, on September 8, 1978 together with 11 other sites from around the world. Indeed, the Wieliczka Mine reflects the progress of mining technology, the development of work organisation and management, and the introducing of industry legislation since the Middle Ages.

Since times immemorial salt was the economic foundation of the state. In the times the of old in the Kingdom of Poland it was used as a legal tender, replacing metal coins. Initially, salt was acquired from brine springs through heating the brine and the vaporisation of water. It is not known when the excavation of rock salt began; most probably, during the digging of the brine wells, a salt deposit was discovered, and its excavation with primitive tools began. The contemporary Polish monarchs quickly realised what value the white ore had and introduced a monopoly on the mining and even the distribution of salt. They knew that salt was a most important commodity, as it was indispensable for survival. Large amounts of salt were needed for conserving meat, butter, and fish, tanning hides, and later also for the production of gunpowder.

The traces of the first plant in which salt was manufactured from brine date back to the Middle Neolithic period (3,500 BC) and were discovered in the area where the town of Wieliczka was later created. Historical records demonstrate that Wieliczka was the largest salt-making centre in the Małopolska as early as in 10th-11th century, and it was known as Magnum Sal, or Great Salt.

The oldest mining (excavation) shaft, discovered in the courtyard of the Żupny Castle in the town of Wieliczka (now available to visitors as an archaeological mining reserve) dates to the mid-13th century. Large-scale mining of salt in Wieliczka began with the construction of the Goryszowski Shaft, which dates back to the 1280s.

The first surviving written record of rock salt deposits in Wieliczka is to be found in the 1290 foundation charter of the town, which of course does not mean that salt had not been produced here much earlier.

At the end of the 13th century, the "Krakow Mines" company was formed, which included the Wieliczka and Bochnia salt mines along with local salt-boiling manufactures. The company functioned in this form for nearly 500 years, until the first partition of Poland (1772), and was the largest salt-production company in the Polish Commonwealth and one of the largest in Europe.

Salt was the most important mineral in the Polish state and in accordance with the laws in force (the so-called salt regale), it was the property of the ruler. It is estimated that during the reign of King Casimir the Great (14th century) revenue from salt sales accounted for one third of the Treasury revenue. The salt mines of Krakow experienced their golden age between 16th and mid-17th century. In the period, the company employed about 2,000 miners, and production exceeded 30,000 tonnes. In the 17th century, salt was mined at Wieliczka at three levels. During this period, eight shafts were excavated (including the Daniłowicz Shaft, which currently is used for tourism purposes). The first maps of the Wieliczka Mine were also created during the period . However, prolonged wars, plagues, and the accompanying natural disasters deeply perturbed the salt economy during the second half of the 17th century, and the Mine managers neglected safety work, which lad to the dilapidation of the Mine . It was only in the following century that specialists, headed by J.G. Borlach, were brought over from Saxony and managed to improve the company management from the organisational and technical point of view.

Under Austrian management (1772-1918) production was greatly increased, which resulted in the spatial development of the Wieliczka Salt Mine, mechanising the mining operation (steam and electric machines), employing professional engineering staff and the creation of the first tourist route for the public.

In 1913, a modern salt-boiling plant was installed in Wieliczka, which created a number of workplaces and prospects for the increase of production; these opportunities were further developed during the inter-war Second Polish Republic. New technology of salt leaching under ground allowed the Mine to achieve high rates of production and the extension of mining activities of the plant. However, extensive exploitation and neglecting current safeguarding work adversely affected the stability of the rock mass and the condition of the Mine. After the Second World War, it was even planned to flood the Mine. In 1964, the mining of rock salt in Wieliczka was discontinued, and on June 30, 1996, the salt bed ceased to be exploited completely. At present, the picturesque mine excavations serve tourism, museum and health purposes.

The Wieliczka salt deposit extends over 5.5 kilometres (East-West) and is between 0.5 and 1.5 km wide (North-South). During seven hundred years, 26 surface shafts and 180 smaller shafts connecting different levels of the mine were excavated. The mining of the salt bed started on Level I (57 m underground), and over time reached Level IX (327 m underground). 2,350 chambers and over 240 km of galleries were carved. Despite the water, collapse and gas threats, the Wieliczka Mine excavations are considerably more durable than those of ore mines, thanks to which chambers excavated at the end of the Middle Ages and the early modern era have been preserved to our day. In order to better protect the most valuable excavations, a historic zone has been delimited in the Mine. As of 2004, it embraced 218 galleries and 190 chambers at Levels I - V, over 20 of which are available to visitors in the Tourist Route (Levels I - III), and 16 at the Museum of Krakow Salt (Level III). The ongoing underground work aims primarily at protecting the Mine’s historical substance. The Wieliczka Salt Mine has the status of a historic monument and is subject to legal protection. In 1976, the Wieliczka Salt Mine was entered in the National Monuments Registry. Two years later, in 1978, the mine was inscribed in UNESCO's First World List of Cultural and Natural Heritage, and it was acknowledged as the National History Monument by the decree of the President of Poland of September 8, in 1994.

Sources

Studia i Materiały do Dziejów Żup Solnych w Polsce, V. I - XXIII (1965 - 2003 r.),
Antonina Keckowa, Żupy Krakowskie w XVI - XVIII wieku (do 1772 r.),Wrocław-Warszawa-Kraków 1969 r.
Dzieje żup krakowskich, Wieliczka 1988
Wieliczka dzieje miasta (do roku 1980), Kraków 1990
Antoni Jodłowski, Żupa Solna w Wieliczce, Wieliczka 2000