The Toplitzsee in Styria, Austria, Province of Ausseerland;

The Toplitzsee in Styria, Austria, is a remote mountain lake known for both its natural beauty and its Nazi history. During World War II, the German navy used it as a secret testing site, and in 1945 crates containing counterfeit British banknotes and documents from Operation Bernhard were sunk there. After the war, legends of a “Nazi treasure” attracted treasure hunters and researchers. Today, the lake is a popular tourist destination where visitors can enjoy nature while also learning about its historical significance.