The lake is filled with water due to its topography formed by a giant landslide that descended from the southern flank of the Messnerin massif towards Trages in prehistoric times.
Grüner See is rightfully considered one of the wonders of Austria. The lake is often called the Emerald Lake because of the special shade of its water. Hiking trails of different lengths and difficulties are arranged along the shores of the lake. Stunning views are along these trails. Diving on the lake is one of the most unusual tourist attractions in Austria.