Freudenburg Castle was built between 1330 and 1337 by John, King of Bohemia and Count of Luxembourg. As part of a castle protectorate between Trier and Luxembourg, it served to secure the road between the cities of Trier and Metz.
During the 15th century the castle fell into disrepair until it was bought by the St. Maximin's Abbey in 1589. They had the castle restored. In a dispute between the abbey and the Archbishop-Elector of Trier; Philipp Christoph von Sötern, the troops of the Archbishop took the castle in 1646 and destroyed it. It was never rebuilt.
Freudenburg Castle was built at the end of a rocky spur. It was separated from the village by a broad dry moat cut out of the rock. Originally a wooden bridge would have given access to the castle from the village. The castle plan follows the outline of the spur, giving it a triangular ground plan.
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.