The Oostkerk was designed by Bartholomeus Drijfhout and Pieter Post and was built between 1648 and 1667. After Drijfhout died in 1651, the building was continued under the Leiden architect Arent van 's Gravezande, who had just completed the Marekerk in Leiden. The white organ was built by Gebr. de Rijckere from Kortrijk in 1782. Two stained glass windows from 1664 still exist in the church, and the klokkenstoel contains a bell by C. Noorden and one by J.A. de Grave, 1715.
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.