St Peter's Church stands at the heart of the upper town, which had fortifications in the Middle Ages. Its entrance portal looks out onto a square on which stand a mission cross and the portal of the clergy house, both classified monuments historiques as well.
St Peter's Church is a former collegiate church with a Romanesque tower and a modern belltower. Its 12th-century nave and side aisles have capitals. The transept also dates back to the 12th century; yet its chevet was modified in the 18th and 19th centuries.
The church houses the tombstone of Saint Euchaire, a 16th-century Renaissance gisant in a funeral niche. The interior is also decorated with 18th-century paintings and old mural paintings.
The western portal was modified but a part of the old sculpture is still visible today.
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.