The fortified citadel at Blaye, standing on the opposite bank of the river Gironde to Fort Médoc, forms, along with Fort Paté, the region's 17th-century defence against river attack.
Built by Vauban, together this group are named the Fortifications of Vauban and are classified as a UNESCO World Heritage Site. The site of the citadel saw its first castle in the 7th century. Vauban's fortress though was built in 1689 and took three years.
The largest of the three fortresses, Blaye has both landward and seaward defences with dry ditches dug out of the rock. He incorporated some of the existing defences into his structure to the benefit of the fort. Some elements are still inhabited today. An impressive spot offering a panoramic view.
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.