Iwonicz Zdroj is one of Poland’s oldest health resorts and spa, dating back to 1578, which was famous outside Poland already in the 18th century. The town lies in the south-eastern part of Podkarpackie voivodship, Krosno province. The town is surrounded on all sides by forests.  The Iwonicz forests create a microclimate around the resort, regulating humidity and temperature of the air, protecting it from winds and are a source of ozone.

The greatest wealth of Iwonicz land are mineral waters and moor mud, which are natural curative agents. These are chloride-bicarbonate-sodium, fluoride, iodide, boric and bromide waters. They are mainly extracted from geological levels so called second and third Ciężkowice sandstone. They are used for drinking therapy, mineral baths, inhalations and production of iodide-bromine salt.