Constantina Castle was dates back to the Moorish period, when it defended the north-south road towards Seville. It was conquered by Christians in 1274 and by the privilege of King Alfonso X in 1253, it passed to the Alfoz of Seville. In 1810, it was used as a fortified point during the period of the French invasion of the town.
Today the castle of Constantina consists of a polygonal enclosure of about ninety metres in diameter, which has an external defence in the form of a barbican, of which there are sufficient remains to affirm that it completely surrounded the enclosure. Most of this area has been preserved, and two of the seven towers that flanked it are still complete, containing magnificently built circular vaulted chambers.
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.