Ragnhildsholmen was a medieval castle built by Håkon Håkonsson (Haakon IV) of Norway around the year 1250. The castle was first time mentioned in 1275. In 1304 it was donated to duke Erik in 1304 and saw the power struggle between Swedish Kings Birger and Magnus III. After the near Bohus Fortress completed, Ragnhildsholmen lost its purpose. It was demolished and stones were probably used to build Bohus. Today impressive ruins still stands on the site.
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.