Mälsåkers Slott on an island in lake Mälaren was the HQ of the Norwegian "police" force during WW2. (Photo by Marcel Burger)

Mälsåkers Slott on an island in lake Mälaren was the HQ of the Norwegian "police" force during WW2. (Photo by Marcel Burger)

Mälsåkers Slott on an island in lake Mälaren was the HQ of the Norwegian “police” force during WW2. (Photo by Marcel Burger)