Grüner See Green Lake
The Grüne See is a karst lake in Styria (Steiermark) on the territory of the municipality Tragöß-Sankt Katharein in the district Oberort. It lies on the south side of the Hochschwabgruppe. The lake is dammed up by a landslide mass which in prehistoric times slipped from the southern flank of the Meßnerin towards Tragöß. As the snow melts on the surrounding mountain slopes, the lake gently fills up with very clear water. The water is therefore cold (5 to 6 °C) and the water level strongly depends on the season. The highest water level is reached in early summer, when the lake is about 10 metres deep at its deepest point. On the southeastern shore there is an overflow with boulders. On the southwest bank you can see how the water flows into the mountain. In autumn it almost completely dries out. Meadows with hiking trails and benches lie above the water level again. Pure water absorbs red light and appears blue-green in thick layers. Finely ground rock suspended in the water reflects the blue-green parts of the light.