The town of Sandanski is located at an altitude of 224 m in the foothills of the Pirin Mountains, along Sandanska Bistritsa river. The resort climate is indeed unique. Throughout the year, local temperatures are higher then inland temperatures - the annual average being 14.7 °C. Winters are mild and short, autumns long and warm. Relative humidity is low (66%), there are over 2436 hours of sunshine a year and fogs are rare. The mineral waters are clear, colorless, odorless and pleasant tasting. They are slightly mineralized, hyperthermal (42-81°C), silicic, with a predominance of hydrocarbonic, sodium, and sulphate ions, and mild concentration of fluorine.
Resort conditions are particularly favorable for treatment of bronchial asthma in its three forms atopic, infectious allergic and combined. By the end of the first week, a marked clinical improvement with fewer attacks both with regard to frequency, strength and duration, is already observed. In more than 55% of the cases the attacks disappear completely.