Colmberg Castle was built in the 13th century and purchased in 1318 by Duke Frederick IV of Nuremberg. In 1791 Colmberg fell under Prussian administration. From 1806 to 1880 it became the seat of the revenue office of the Kingdom of Bavaria. In 1927-1964 it was owned by the last Imperial Consul in Japan. Int1964 Unbehauen family of Colmberg bough the castle and started to reconstruct it into a comfortable hotel.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.