The Royal castle of Děvín was obviously founded at the locality of a previous fortress in the middle of the 13th century. King Wenceslas II gave it to Jan of Michalovice in 1283.
During the 1359 - 1516 period it was (with several breaks) in the possession of the noble family from nearby Stráž (Vartemberk). Then it was purchased by the Biberštejn family who had it renovated. In 1645 it was damaged and burnt by Swedish troops, which is the end of its history.
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.