Gothic Church of St. Catherine was built between 1310-1370 by the Teutonic Knights. In the years 1554-1598 it was used by Lutherans. After damage in 1631 and 1648 was renewed in the 2nd half of the 17th century. Three-nave hall church with square-closed chancel and the west facade with tower from the 15th century. Inside there are 15th-century starlike vaults, fragments of wall murals: Gothic, Renaissance from about 1582, and the Baroque of the turn of the 18th century. Gothic sculptures include 12 apostles at the pillars of the aisle, the crucifix dates from the late 1500s and group of the Crucifixion from the beginning of the 16th century. Renaissance stalls date from 1583.
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.