Fort Heldsberg - Credit: Wikimedia Commons
Fort Heldsberg - Credit: Wikimedia Commons
Fort Heldsberg was built 1938–1940 near St. Margrethen in Switzerland, overlooking the Rhine, which forms the Swiss-Austrian border at that location, just south of Lake Constance. The fort was part of the Swiss Border Line defenses, built between 1938 and 1941. Read more on Wikipedia
Source: en.wikipedia.org