The Estany de Sils is a wetland with unique characteristics in Catalonia. Much of this uniqueness is due to the relatively humid climate and the marked thermal inversion of the bottoms of the Selva center.
Thus, despite its location very close to the Mediterranean, the Estany de Sils has landscapes typical of colder and wetter regions, mixed with typically Mediterranean vegetation in the driest and sheltered areas of the surroundings.
The diversity of aquatic habitats favors the presence of a rich and varied fauna. All this makes the Estany de Sils, despite its small size, has great relevance in terms of biodiversity conservation.
Water birds are probably the best known and most colorful inhabitants of wetlands. Every year millions of these birds make a long round trip from northern Europe to warmer areas where they spend the winter. It is then when many stop at the Estany de Sils.