Burg Dreckberg, likely built between 1347 and 1357 by Paderborn Cathedral Provost Otto von Bentheim, served as a fief for the Lords of Drewer. The bishops of Paderborn constructed it for territorial security against the Electorate of Cologne and the Hellweg route. First mentioned in 1386, the castle withstood the Soest Feud in 1444. Changing hands multiple times, it underwent renovations in the 18th century, acquiring its current baroque appearance. Acquired by the city of Salzkotten in 2000 and later sold to Erhard Christiani in 2002, he utilized it until his death in March 2017.
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.