Grüner See (Green Lake) is a en.wikipedia.org/wiki/Lake in en.wikipedia.org/wiki/Styria en.wikipedia.org/wiki/Austria near the town of en.wikipedia.org/wiki/Trag%C3%B6%C3%9F . The lake is surrounded by the en.wikipedia.org/wiki/Hochschwab mountains and forests. The name "Green Lake" originated because of its emerald-green water. The clean and clear water comes from the en.wikipedia.org/wiki/Snowmelt from the en.wikipedia.org/wiki/Karst mountains and has a temperature of 6–7 °C (43–45 °F) During the winter, the lake is only 1–2 m deep and the surrounding area is used as a county park. en.wikipedia.org/wiki/Gr%C3%BCner_See_%28Styria%29#cite_note However, during the spring, when the temperature rises and the snowmelts, the basin of land below the mountains fills with water.http://en.wikipedia.org/wiki/Gr%C3%BCner_See_%28Styria%29#cite_note-dailymail-2 The lake reaches its maximum depth of around 12 m from mid-May to June and is claimed to look the most beautiful at this time. In July, the water begins to recede.