Largo di Torre Argentina is a square that hosts four Republican Roman temples, and the remains of Pompey's Theatre. The name of the square comes from the Torre Argentina, which takes its name from the city of Strasbourg, whose Latin name was Argentoratum.
The four temples, originally designated by the letters A, B, C, and D, front onto a paved street, which was reconstructed in the imperial era, after the fire of AD 80. The area was delineated to the north by the Hecatostylum (one-hundred columns porch) and the Baths of Agrippa, and to the south by the buildings related to the Circus Flaminius, to the east by the great porched square of Porticus Minucia Frumentaria, and to the west by the Theatre of Pompey.
Julius Caesar was killed in the Curia of the Theatre of Pompey, and the spot he was believed to be assassinated is in the square.
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.