The Château du Birkenfels is a ruined castle in the commune of Ottrott. Originally it was built by Burkhard Berger, a vassal of the bishop of Strasbourg, in the 13th century. The castle's position allowed surveillance of the old Roman road running from Mont Sainte-Odile to Champ du Feu and the valley of the Bruche.
The construction is dated to around 1260. The earliest recorded mention is from 1289. The entrance tower to the house and the lower courtyard are from the late 15th or early 16th century.
The castle belonged the Berger family until 1532, then to the Mundolsheim family until the French Revolution. The castle fell into ruins after the Thirty Years' War and was taken over by the town of Obernai, becoming part of the continuous forest between Obernai and Bernardswiller.
The castle is today in a poor state. Remains include the ditch, wall, keep and lower courtyard.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.