The Baths of Caracalla were the second largest Roman public baths, or thermae, in Rome. It was built between AD 212 and 217, during the reigns of Septimius Severus and Caracalla. They would have had to install over 2,000t of material every day for six years in order to complete it in this time.
The baths remained in use until the 6th century when the complex was taken by the Ostrogoths during the Gothic War, at which time the hydraulic installations were destroyed. The bath was free and open to the public. The earthquake of 847 destroyed much of the building, along with many other Roman structures.
The building was heated by a hypocaust, a system of burning coal and wood underneath the ground to heat water provided by a dedicated aqueduct. It was in use up to the 19th century. The Aqua Antoniniana aqueduct, a branch of the earlier Aqua Marcia, by Caracalla was specifically built to serve the baths. It was most likely reconstructed by Garbrecht and Manderscheid to its current place.
In the 19th and early 20th century, the design of the baths was used as the inspiration for several modern structures, including St George's Hall in Liverpool and the original Pennsylvania Station in New York City. At the 1960 Summer Olympics, the venue hosted the gymnastics events.
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.