Mersch Castle is one of the castles belonging to the so-called Valley of the Seven Castles. The castle was built in the 13th century by Theodoric, a knight in the service of Countess Ermesinde of Luxembourg. It was captured and burnt down by the Burgundians. In 1574, Paul von der Veltz transformed the building into a comfortable castle in the Renaissance style. The keep had large windows and the property was surrounded by a protective wall with seven towers. Finely vaulted ceilings were erected over the rooms on the ground floor and the first floor. The Knights' Hall on the second floor has a magnificent chimney. The arms of 16 noblemen decorated the walls. In 1603, the castle was again destroyed by the Dutch. In 1635, during the Thirty Years' War, the castle and the village were left in a sorry state. However, around 1700, it was once again repaired, this time by Johann-Friedrich von Elter who rebuilt the gate and appended his coat of arms. The chapel was restored in 1717 by von Elter. The altar bears the arms of the castle's heiress, Charlotte von Elter.
In 1898, the Sonnenberg-Reinach family sold the castle to a businessman called Schwartz-Hallinger. In 1930, restoration work was carried out by the owner M. Uhres. In 1938, a youth hostel was housed in a new building adjacent to the castle. From 1957, the commune acquired the building but sold it to the State of Luxembourg in 1960. As a result of an exchange agreement, the commune finally regained ownership in 1988 and undertook substantial renovation work for the needs of itse administrative services which now occupy the building.
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.