Trekroner Søfort (Three Crowns Sea Fortress) is a sea fortress at the entrance to the Copenhagen harbour. From 1713 until after World War I, Trekroner Fort was part of the fortifications of Copenhagen.
The original location of Trekroner Fort was a few hundred meters north of the current one. In 1713, three old line ships were sunk to form the basis for a battery. One of the ships was called Trekroner, and she gave her name to the fort. The construction of the current fort began in 1787. The fort was an important part of the Danish line of defense during the Battle of Copenhagen in 1801. The fort also was engaged during the British attack on Copenhagen in 1807.
From 1818 to 1828 and in 1860, the fort was strongly enhanced, but its military significance diminished after the First World War. In 1934 it was sold to the Copenhagen harbour services. During the German occupation of Denmark the Germans used the fortress as a barracks. After the war it fell vacant until 1984, when it was opened to the public.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.