Duzdag, 12 km from the town of Nakhchivan, is a former salt mine. Its underground tunnels at a depth of 300 meters have now been turned into a first-class speleotherapy center, where a professional team of doctors and physiotherapists help adults and children fight respiratory diseases. Ideal conditions are created in the depths of the salt mine: low humidity, constant temperature (17-18 degrees Celsius), the air is saturated with iodine, calcium, sodium ions, it is free of heavy metals, allergens, and microbes. Treatment with pure natural salt is highly effective: according to statistics, adults with bronchial asthma are cured by 80-86%, and children - by 96-98%.