The Wildsee is a small lake within a moor between Bad Wildbad and Gernsbach on top of the Northern Black Forest mountain range in southwestern Germany. The lake is fed by rain water. It is part of the Kaltenbronn nature reserve. The area has a geological base of sandstone. The sandstone developed a rich brown soil, which originally allowed the European Beech to grow. In the later development of forestry, the Norway Spruce and European Pine (Pinus sylvestris) were introduced. These three tree species can be found in the surroundings of the lake.