Niedermunster Abbey, situated at the foot of Mount Saint Odile was founded around 700 AAD by Saint Odile of Alsace, who was also the first Abbess.
Until the end of the 12th century, the two abbeys formed a single institution, but from the beginning of the 13th century, they began to operate as separate establishments. In 1542 the abbey came under the authority of the Great Chapter of Strasbourg Cathedral.
The Abbey buildings of which the ruins are still visible today were built between 1150 and 1180 AD. The Abbey was seriously damaged during the Peasants' War in 1525 and again by two fires, in 1542 and 1572. The nuns abandoned the abbey in 1545 and it was never reoccupied.
The site was then used, up until the 19th century, as a quarry for other buildings, including the adjacent farm.
For several centuries the abbey was known for its relics, the head and arm of Saint Lazarus of Marseille. When the abbey was burnt down these were transferred to Andlau, eventually disappearing during the French Revolution.
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.