Hagby Church is one of Sweden's few preserved round churches, and is considered by many to be the best preserved one in the country. The predecessor of Hagby stone church was the wooded Saint Sigfrid chapel, which was located about two kilometres south of the present church structure. The construction of this stone church began in the late 12th century. By 1541 it was abandoned.
The structure was meant to serve both as a sanctuary and a fortified building. As a result, the upper part of the walls has openings for shooting and spear throwing. The most recent renovation has attempted to emphasize the old nature of the building, so that it is now perhaps the best example of round church architecture, which otherwise is generally mostly found on the island of Bornholm. The triumph crucifix and font dates from the Middle Ages, but the interior is mainly from the 17th and 18th centuries.
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.