Grüner See, the “Green Lake”, is located in Sryria, Austria. Based at the foot of snow capped mountains, the lake is only 1-2 meters deep during winter, and the surrounding area is used as a county park that is a favourite site for hikers. But during spring, the temperatures rise and the ice and snow from the mountains melt into the basin below, flooding the park area; during summer, the lake can reach depths of 12 meters. The green grass and flowers of the meadow can be seen in full bloom underwater, tinting the lake a distinct green colour, while the ice-cold water provides crystal clear views. Check out the gallery above to see these unique scenes of underwater benches, bridges and walking trails.