Ortenburg castle in Bautzen stands on the site of 7th century fort enlarged by Henry I in the 10th century. In the 15th century the castles was rebuilt in the late-Gothic style by Matthias Corvin, King of Hungary, following two devastating fires. The tower on the north wing still bears a relief representing the king. In 1698, at the height of the Baroque period, three Renaissance gables were added to the castle.
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.