The structure of the St Peblig's Church has thirteenth century origins although much of the present fabric is of the fourteenth century. A tower and chapel were added in the sixteenth century, and there were further minor alterations in the eighteenth and ninteenth centuries before major restoration work was undertaken in 1894.
The church is constructed of coursed rubble walls with a slate roof and coped gables. It is notable for its imposing 3-storey western tower and has a high quality, late medieval arch-braced roof. There is a sixteenth century alabaster tomb in the north-eastern chapel, and some evidence of wall painting, including scrollwork in a tomb recess that is probably of medieval date.
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.