The Site comprises a network of natural mid-mountain volcanic and glacial lakes and peatlands of high ecological value. It contains 178 peatlands covering over 4,600 hectares, which form a diverse complex of wetlands, ranging from fens fed by groundwater to bogs fed by precipitation. This interconnected system supports threatened species including the Eurasian otter (Lutra lutra) and the large blue butterfly (Phengaris alcon). It is a breeding site for the violet copper butterfly (Lycaena helle), which is endangered in Europe, and harbours the nationally vulnerable crescent bluet (Coenagrion lunulatum) and the Siberian leopard plant (Ligularia sibirica), species of European conservation significance for which the Massif Central constitutes an important refuge. The Site is also important for endemic fish species, such as the bullhead (Cottus perifretum). It provides ecosystem services including drinking water, climate regulation, and recreational hunting and fishing; it is also used for scientific research and environmental education.