Lopera Castle is a big castle in the city center made up of irregular masonry. It has an irregular pentagonal base. The castle is defended by five towers, some of the towers are cylindrical and some others are prismatic. It has machicolated balconies, a defensive device to better guard entrances and some of the fortified towers.
There were Romans and Visigoth settlements until Lopera was conquered by the Muslims at the beginning of the 8th century. During the 9th and 10th centuries, the population moved to the current town where a small Muslim farmstead was created. During the 11th century, the farmstead was fortified as a defence against Castilian attacks.
Once Lopera was conquered by the Christians, King Ferdinand III relinquished it to the Order of Calatrava. The Order of Calatrava built the castle that exists today. This castle guaranteed an escape to river Guadalquivir.
In 1856, the castle was acquired by Alonso Valenzuela who turned it into public property.
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.