The American Hotel, locally known as the Hotel Americain, was built in 1898-1900 by W. Kromhout and W. G. Jansen in the Berlage style. In 1927-1928 an expansion was realized from a design by the architect G.J. Rutgers in collaboration with K. Bakker in 1927-1928. Both the expansion and the café are National Heritage sites. The Amsterdam American Hotel is a member of Historic Hotels Worldwide.
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.