St. John the Baptist Church is considered to be the acme of the Yaroslavl school of architecture. It was built in 1671-1687 on the bank of Kotorosl river. Its walls and dome drums are covered with richly glazed tiles; the temple's fifteen onion domes are assembled in three groups. The 7-storey, 45-metre high bell-tower was built later than the church itself in mid-1690s. The entire interior is covered with frescoes depicting Christian saints, St. John the Baptist hagiography and biblical topics. They were painted by Dmitry Plekhanov and Fyodor Ignatyev in 1694-1695.
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.