Oscarsborg Fortress, Harbour fort in the midle. «Kongen» - the flagg pole of Oscarsborg up to the left and the shadow near the water at bottom right is the exit tunnels from the torpedo battery.
<a href="//commons.wikimedia.org/wiki/User:Minto" title="User:Minto">Minto</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>