Just in front of Vlaherna Monastery there is an island called Pontikonissi on which there is only one building: the church of Pantocrator. According to one interpretation of the Odyssey this island would be the ship of Ulysses that was turned into rock by Poseidon while, according to another legend would be the rock on which Ulysses' ship crashed during a storm.
The church of Pantocrator was built in the 13th century and to visit it you can take a boat from the small port opposite. The Byzantine chapel that is on the top of the island encloses the memorial tablets of Elizabeth Empress of Austria and Rodolfo archduke.
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.