In the 1970s, the partially desolate Rosenau Castle underwent extensive renovation by the new owner, the Province of Lower Austria.
Under many layers of overpaintings suddenly appear beautiful frescoes with clearly Masonic symbols, which reveal a huge universe of allegorical scenes and thus encrypted reflect the humanistic ideas of the 18th century. A Masonic ritual room (temple) from the time of its creation (1736 - 1748) is rediscovered, brought back to its original condition and furnished with appropriate furniture from that period.Today it is used again for ritual Masonic gatherings and is considered the oldest ritual room used by Freemasons in continental Europe.