The Glehn Castle or manor was established by Nikolai von Glehn on the northern part of the lands of his Jälgimäe Manor to become his new residence. The castle was completed in 1886 and was designed by himself. The castle is surrounded by a park with several buildings like palm house (1900–1910), observatory tower (1910) and sculptures Kalevipoeg (1908), Crocodile (1908), all of those designed by Glehn himself.
After Glehn emigrated to Germany in 1918 the castle was looted and fell into decline. In the 1960s, restoration of the building commenced. The renovated palace was inaugurated on the 24 March 1977.
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.