The fortified-looking church of Santa María of Baiona, with a Ogival Romanesque style, was built in the 13th century and had the category of collegiate church from 1482 to 1850.
It is divide up in three naves with their respective rectangular apses. The main nave resembles the Cistercian style of Santa María de Oia monastery. Two buttresses flanked the front door in the main façade: three pairs of columns, flat tympanum and archivolts. Windows are Romanesque; there is a marvellous Romanesque rose window up in the main façade. In 1841 several crosses of different styles formerly placed around the village were moved to the portico.
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.