Strangford Castle appears to be a small tower house from the late 16th century, but a blocked door of 15th century type at first floor level, seems to indicate the remodelling of an earlier tower. The current entrance, in the north-east wall, is a reconstruction, positioned by the surviving corbelled machicolation above and a socket from a draw-bar to secure the original door. The original entrance may have been on the first floor. It is a small, rectangular, three-storey tower house with no vault or stone stairway. The first floor fireplace has an oven. The ground floor chamber is lit only by small gun-loops. The roof has very fine crenellations, again with pistol-loops. The original floors, like their modern replacements, were made of wood.
References:Towering 52 meters above the sea, Bengtskär lighthouse is the tallest one in Scandinavia. The building started in in 1905 after the shipwreck of S/S Helsingfors and was completed in 1906. The lighthouse was designed by architect Florentin Granholm. On December a special petrol lantern, designed and built in Paris, was brought to Bengtskär and installed atop the tower.
German fleet bombarded Bengstkär in the First World War in 1914. Since the Gulf of Finland was heavily mined, it was not until 1919 that the surrounding seas were declared safe for shipping, that the light was lit again.
After the war the military value of Bengtskär increased as part of the defence system of independent Finland. In Second World War (1941) Soviet Union made a suprise attack to island. After a bloody battle, the small Finnish garrison emerged victorious. Intermittent repairs to the facility continued during the post-war period.