Situated on the left bank of the Navia Estuary, Castro de Coaña is a hilltop settlement (4th Century BC) surrounded by walls and accessed from the south. The main defensive structure is located precisely in the south and consists of a wide ditch dug into the slaty subsoil finished off by a wall. Inside, the settlement is divided into several sectors.
It has a diamond shape in which the three areas can be clearly distinguished. The acropolis is a triangular enclosure surrounded by a wall, not used for housing. Access to this area was protected by a square tower. The northern residential sector spreads out beneath the north wall of the acropolis, mostly consisting of circular huts. Some of them are accessed via a hall or corridor. The walls are made of slate with rounded corners.
Inside the residential sector near the gate to the acropolis, there are two groups of buildings associated with channelling water and a pool, a granite vessel called a 'bath', which suggests that it was used for bathing or rustic saunas.
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.