Grüner See (Green Lake) is a lake in Styria, Austria, surrounded by the Hochschwab Mountains and forests. The name “Green Lake” originated because of its emerald-green water. During winter, the lake is only 1–2 m (3–7 ft) deep and the surrounding area is used as a county park. However, in spring, when the temperature rises and snow melts, the basin of land below the mountains fills with water. The lake reaches its maximum depth of around 12 m (39 ft). The waters are at their highest in June when it becomes a destination for divers keen to explore the rare phenomenon. A bridge and a bench could also be found underwater, as well as trails and trees.
info wikipedia
By Herzi Pinki (Own work) [GFDL, CC-BY-SA-3.0 or CC BY-SA 2.5], via Wikimedia Commons
By TauchSport_Steininger – Flickr: 2006 – Grüner See, CC BY 2.0, Link
By TauchSport_Steininger (Flickr: 2006 – Grüner See) [CC BY 2.0], via Wikimedia Commons
By TauchSport_Steininger (Flickr: 2006 – Grüner See) [CC BY 2.0], via Wikimedia Commons
By TauchSport_Steininger – Flickr: 2006 – Grüner See, CC BY 2.0, Link
By Martin Toedtling (Own work) [CC BY-SA 3.0 at], via Wikimedia Commons
e MORFES 
Your photos are so clear.. Beautiful..
It is really beautiful.
Paesaggi meravigliosi da vivere…
Cari saluti,silvia
Strange to see the walking path and the bench under water. Great environment.
The photos, well made, will certify the beauty of this Austrian lake. Really the color of the waters, they have an unusual green. This is where its appeal stands out the most. A dream to rest in all that natural beauty that surrounds it. Greetings and a good afternoon to you.
Manuel Angel from Chile.