While today salt is a cheap commodity, such was not the case in the Middle Ages, when refrigerators were not yet invented and the only way to preserve food was by packing it in salt. Hence, it was not surprising that salt mines were worth their weight in gold - Literally.
Poland's Wieliczka salt mine was so lucrative, that it provided a third of the country's annual revenue. The mineworkers also did every well. However, it was a hazardous job, one in which over ten percent of the workers perished annually - either from mining accidents or sheer exhaustion.
Therefore, it was not surprising that miners sought solace from a higher power, by starting their day with a prayer. By 1689, they had even dedicated a chamber to St. Anthony, the Patron Saint of Metal Miners and begun holding daily mass readings.
In order to create a real church-like environment, the workers began to carve out statues, both free standing and on the mine walls - Using just the rock salt that lay around them. Over the centuries, they created over 2,000 galleries that extended out 265 million cubic feet. While the initial sculptures were carved by the mineworkers, as years went by, some professional artists joined in the effort too. The result, was the creation of a magical world that is intact till today, long after the miners have moved on.
One of the most prominent galleries created was the main cathedral, a large room that features not only incredible carvings, but also, chandeliers that were made by mixing in rock salt with impurities, to create a glass-like effect. The room also features a series of three-dimensional scenes carved deep into the cavern's walls - Amongst them, is a rock-salt depiction of Leonardo Da Vinci's Last Supper.
While commercial mining was halted in 1996, the mine continued to produce table salt until 2007, when it was finally shut down thanks to low salt prices and flooding in some areas. Today, a small portion of this underground magical world that lies 400 feet below the ground is open to the public - for both tourists, as well as, the residents of Wieliczka who use it as a place of worship and even for weddings and banquets. In 1978, the salt mines were added to UNESCO's World Heritage list, an honor bestowed to less than 1,000 places in the world. The best part about being on this list is that the organization ensures that all appropriate measures are taken to preserve the place forever!
Resources:europeupclose.com,odditycentral.com, wikipedia.org