The title means the front (or first) lake Gosau. It’s so called because it is the first of three successive lakes, namely Vorderer Gosausee, Gosaulacke and Hinterer Gosausee. The peak on the horizon, just above the glacier, is Dachstein, which at 2995 metres is the highest peak in Salzkammergut. By some geological coincidence the three lakes, glacier and Dachstein are all aligned in one straight line!
Photo was shot in Salzkammergut, Austria. Image is best viewed large.