The Fortress San João Baptista da Foz do Douro was built in the late sixteenth century to better protect the coast and the mouth of the Douro River. The monument is occupied today by the Regional Delegation of the Institute of National Defense. It is a fine example of military architecture. The original basic structure was enhanced with more recent bulwarks. The Lawn Tennis Club da Foz is located at the foot of the Fort.
Visits to the Fort are free on weekdays between 9h and 17h30. There are no official guided tours, but if you are part of a large group, it is advisable to contact the Fort ahead of time to ensure that the visit does not disturb its activities.
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.