Grüner See, Tragöß (TILOS / no diving)
Diving is prohibited. The Grüner See near Tragöß at the foot of the Hochschwab was once one of Austria's most famous dive sites: in winter it is only 1–2 m deep, but snowmelt raises it to about 12 m from mid-May to June, flooding the surrounding meadow, a trail, a bench, a bridge and trees. Because hundreds of divers came on peak weekends and stirred up the bed, threatening the lake's colour, the Tragöß tourism association announced an indefinite ban from 1 January 2016, and water sports are no longer allowed.
depth: 0–12 m