The Ahrensburg village came into the possession of the Cistercian Reinfeld Abbey in 1327. After the dissolution of the monasteries due to the Reformation, the whole area came into the possession of the king of Denmark. He rewarded his general Daniel Rantzau 1567 with lordship over these villages. His brother and heir Peter Rantzau built a Renaissance residence in the form of a water castle, now the symbol of the town, and the castle church around 1595. The new schloss buildings were made with parts of the torn-down mansion, on a rectangular island surrounded by a defensive moat. The following year, the chapel was completed. It was modelled on Schloss Glücksburg, built a few years earlier. Four octagonal towers were added later with copper-covered torn heads and lanterns.
The Rantzaus' estate was heavily indebted by the middle of the 18th century and, in 1759, was acquired by the businessman Heinrich Carl von Schimmelmann. Schimmelmann remodelled the castle and village in the baroque style and the current layout of the town reflects these plans.
Historians in Germany consider the building one of Schleswig-Holstein's best-known Renaissance buildings and attractions. Open to the public, it is surrounded by an English park, a chapel, a watermill and a museum.
References:Château de Niort is a medieval castle in the French town of Niort. It consists of two square towers, linked by a 15th-century building and dominates the Sèvre Niortaise valley.
The two donjons are the only remaining part of the castle. The castle was started by Henry II Plantagenet in the 12th century and completed by Richard the Lionheart. It was defended by a rectangular curtain wall and was damaged during the Wars of Religion. In the 18th century, the castle served as a prison.
The present keeps were the central point of a massive fortress. The southern keep is 28m tall, reinforced with turrets. The northern tower is slightly shorter at 23m. Both are flanked with circular turrets at the corners as well as semicircular buttresses. Each of the towers has a spiral staircase serving the upper floors. The Romanesque architecture is of a high quality with the dressed stones closely jointed.