This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Old gun emplacement fence. The old gun emplacement at Fjell Festning Fjell Fortress as it appeared in mid The gun was the Btower from the German battleship Gneisenau The steel plating lying in front in the picture is armour from the now removed gun turret The emplacement has later been modified and large glass housing has been placed