Entrance to fuel storage room in Siarö Fort. Siarö Fortress situated on Kyrkogårdsön in the middle of the channel between Vaxholm and Furusund. Built after the defence decision of 1914, when Vaxholm Fortress was to be reinforced by an outer line of defences consisting of forts and artillery batteries. The fort was closed in 1939 (after moving the coastal defences out to the outer edge of the archipelago).