Originally built in the 11th century, when the Normans fought the Byzantine rulers in Southern Italy, the Corigliano Calabro Castle expanded in the first half of the 1300s thanks to the powerful Sanseverino family. In the 15th century, the castle was renovated and its architecture took on the typical features of the Aragonese style; the structure was further altered in the 17th century by the Saluzzo family, and in the 19th century by the Compagna family.
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.