This is one corner of the Toplitzsee in the Salzkammergut in the Tyrol. According to legend (never verified), the Nazis sunk a fortune in gold bullion into the center of the Toplitzsee. The lake, incidentally, is incredibly deep, and none of the gold has turned up to date. If you’d like a fictionalized account, check out Helen McInnes’ “The Salzburg Connection”.
On the other hand, the Salzkammergut figured prominently as a hiding place for stolen art – the salt mines in the area were perfect for storing huge numbers of paintings, sculptures and other objects. The recent film “The Monuments Men” is a fairly accurate portrayal of the mines, the process of retrieving the art objects, and the removing of purloined objects from their “borrowers”.