Ventlinge Church, dedicated to St. Lawrence, was built during the first half of the 1100's. It began as a towerless vestibule church of Romanesque style. Around the year 1200, a defensive tower entirely on its own grounds was added. Above the staircase entrance in the porch is a throw shaft straight up through the wall. Church defenders could also stand on the tower’s second floor and throw stones at unwelcome visitors. In 1812, the church was repaired and rebuilt so its medieval character was lost. The lantern was added to the tower in 1825.
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.