The Site consists of peat bogs and transitional mires along the flood plains of the Izera River in the central Izera Mountains, on Poland’s south-western border with the Czech Republic. It is the largest mountain bog complex in Poland, with no equivalent in any other part of the country. The mires feature subalpine tundra vegetation, and the peat bogs host communities which are significantly rare in mountain areas of the Continental biogeographical region. Species of European importance include the Boreal owl Aegolius funereus, the Eurasian eagle-owl Bubo bubo and the Eurasian black grouse Lyrurus tetrix. The mires play important roles in flood protection, by capturing the spring floods of the Izera River and its tributaries. Other important functions of the wetland are carbon sequestration and storage, and soil formation. It also provides scientific and educational opportunities. It is adjacent to similar large mire complexes on the Czech side of the River, which have been designated as Jizera Headwaters (Ramsar Site no. 2074).