A young Aristocrat, Leopold Christoph Graf Schallenberg, converted his inherited property around Rosenau into a representative castle in the early 18th century.
The substance of this building has remained unchanged for 270 years and is considered a masterpiece of baroque design. Schallenberg employs some of the most important artists of his time. For example, the baroque master builder Joseph Munggenast (nephew of Jakob Prandtauer), who previously worked on the construction of the Melk, Altenburg and Zwettl monasteries.
Top artists of the baroque period created a true universe of Masonic symbols. They can be found in the frescoes by Bartolomeo Altomonte, Daniel Gran and above all by the architectural painter Johann Rinculin.Today the castle, owned by the Province of Lower Austria, houses the Austrian Masonic Museum, a bookshop, a café-restaurant, a hotel and rooms for events.