Short Story:
At April 4th, 1940 the “Battle of the Drobak Sound” (Wikipedia) took place in southern Norway when the German heavy curiser Blücher tried to break through to Oslo and was sunk by the 28cm coastal artillery and torpedo batteries at Oscarsborg Festning (Fortress).

In Game:
We’ve implemented Oscarsborg Festning as a “Point of Interest” in Command Of The Sea. These are locations in our open world where we’re using a much higher landscape-resolution and pay special attention to details which involves a lot of “handcrafted” 3D-Models.
At our actual state of development (October 2018) we’d like to implement some AI coastal artillery there, which should serve as a intermediate step towards smart enemy AI-Ships.
Feel free to compare our reproduction with the real location on Google Maps, although some details have changed during the last 80 years, as it’s now polished up as a tourist attraction.

More Info about Oscarborg Fortress at Wikipedia