Salt caves are not a new phenomenom. The first mentions of the therapeutic use of salt caves are from way back in the 19th century when the Polish physician Felix Boczkowski discovered that workers in the salt mine of Wieliczka in Poland were having far less respiratory problems than other people. In 1839 he opened the first facilities in the salt mine.
Going even further back in history, in the Grecian age, Hippocrates recommended salt inhalation as an effective treatment for respiratory issues!
In the 1950’s this concept called Halotherapy was rediscovered and went into a new stage with the help of Eastern European physicians and engineers who found a way to stimulate the natural conditions of salt caves and many new halotherapy centers were opened all over Eastern Europe and Scandinavia.