The Museo delle Mura ('museum of the walls') provides an exhibition on the walls of Rome and their building techniques, as well as the opportunity to walk along the inside of one of the best-preserved stretches of the Aurelian Wall. The museum is free of charge.
The museum in its present form, was officially opened in 1990. Prior to 1939, the Porta San Sebastiano (also known as the Porta Appia) had been open to the public but it was then taken over by Ettore Muti, the Secretary of the Italian Fascist Party. White-and-black mosaics in some rooms date back to that time. From 1970, there was a small museum connected to the internal parapet of the Aurelian Wall but this museum was only open to the public on Sundays, and, after a few years, was closed.
The museum provides a detailed history of wall construction in Rome and the surrounding areas, with information going back to one constructed in Ardea to the southeast of Rome in the 8th century. It describes the construction methods of the first Roman wall, built by Servius Tullius the legendary sixth king of Rome, the second wall constructed in the 4th century BC after invasion of Rome by the Gauls, and the Aurelian Walls, constructed in the 3rd century CE, as well as subsequent work to raise the height of those walls and improve defences, and more recent additions and changes up to the 20th century. In addition to text and diagrams, some models of walls are provided.
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.