Schönbühel castle origins date from the early 12th century. The castle is built on rock approximately 40 metres above the level of the river Danube. A Roman fortress may have stood there before. The castle was begun in the early 12th century by Marchwardus de Schoenbuchele as a defensive fortress. When his descendant Ulrich von Schonpihel died at the beginning of the 14th century, the family was extinguished. The castle was briefly owned by Conrad von Eisenbeutel, and then by the Abbey of Melk. In 1396 it was sold to the brothers Caspar and Gundaker von Starhemberg. It remained in the Starhemberg family for more than 400 years, but fell into disrepair.
In 1819 Ludwig Josef Gregor von Starhemberk sold it, together with the castle of Aggstein, to Count Franz von Beroldingen, who had it renovated and partially rebuilt, so that by 1821 it was again habitable.
In 1930 the Schönbühel estate was sold to Count Oswald von Seilern und Aspang.References:
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.