late Gothic Castle Semple Collegiate Church is under the protection of Historic Environment Scotland as a Scheduled monument.
John Sempill, 1st Lord Sempill founded the collegiate church near Castle Semple, in circa 1504. It had a provost, six chaplains or prebendaries, two boys, and a sacristan. The roof was removed in the 1800s, and the ivy has penetrated into the interior. The building is a simple oblong, terminating toward the east in a three-sided apse, and having a square tower projecting from the centre of the west wall. The forms of the double windows indicate that they are very late survivals of Gothic architecture. The other windows in the side walls are altered, but they do not present any features like those of the apse.
Over the door to the chancel are two coats of arms with the letters R. L. S. and A. M. S., one shield bearing the Sempill arms and the other those of Montgomerie. The square tower at the west end is extremely simple. The tower and most of the side walls are of about the date of the original foundation, while the east apse has been added in the 16th century, to receive the monument of John, Lord Sempill, who died at the Battle of Flodden in 1513. A few remains of the original squareheaded windows in the side walls are still traceable. The interior was divided by two solid walls into three compartments, so as to form separate private burial places. In the eastern compartment, there is a large monument to Lord Sempill. A monumental slab in the central compartment is erected in memory of Gabriel Sempel, who died in 1587.
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.