Montorio Castle was presumably a look-out post which was once part of the Verona city fortifications and which is first mentioned in documents dating back to 995 AD. It was subsequently rebuilt by the Aldobrandeschi in the Middle Ages and restructured by the Ottieri and then transformed into a fortified farmhouse after the annexation of the county in the Grand Duchy of Tuscany. Only certain sections of the structure remain, as four of the seven towers were demolished (as well as parts of the walls) by the Austrians in 1820. The castle now serves as a venue for cultural events held in the summer.
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.