The Bertradaburg is a ruined hill castle on a rock spur above the village of Mürlenbach in the county of Vulkaneifel. The castle was built on the remains of a Roman castrum, which probably guarded the Roman road from Trier to Cologne. In the castle, according to local tradition, Bertrada, the mother of Charlemagne is said to have lived which implies that his birth was around 747 AD. The existence of the castle is first recorded in the 13th century when it is mentioned as a state fortress of the princely imperial abbey of Prüm (c.f. the Middle Rhine Register or Mittelrheinisches Urkundenbuch), archaeological finds have indicated that there were earlier fortifications on the site.
After Prüm Abbey was occupied and damaged by French Revolutionary troops from 1794 to 1802, Mürlenbach's castle was seized as part of the forced secularisation of the abbey estate and auctioned by France to a private owner.
In the late 20th century, the surviving castle walls and buildings were restored by the Tiepelmann family and the state-owned, 30-metre-high, ruined double tower gate was rebuilt with state finance. In 2009, the nine owners were given a grant from the federal and state budgets to secure and maintain the 16th-century, five-metre-thick, southwest roundel. The 13th-century shield wall was also renovated with funding from the state of Rhineland-Palatinate.
The 30-metre-high tower house, the double tower gateway of the Betradaburg, is visible from a long way off. It has good views of the surrounding countryside and may be visited as part of a guided tour. Every year the Mürlenbach Castle Festival (Mürlenbacher Burgfest) takes place. The castle is privately owned and has holiday apartments which are currently being renovated.
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.