History of Waldschlössl is full of movements. It used to be the first lordly property in the upper Schwarza valley around 1150. From this period, there are no surviving walls left. After several years of serving as an agricultural holding, it became the property of banker Knöpflemacher from Vienna in 1881 who built a big villa in this area. Archduke Leopold Salvator of Austria, prince of Tuscany spent the summer with his family here in 1901. In the very same year, the villa became the property of architect Franz Kupka who designed many buildings in Vienna, mainly on the Mariahilfer Strasse. He was responsible for the extension of the villa and due to him the construction has its current appearance. He sold the building to Sophie Kolm in 1904. Susbsequently, Waldschössl served as a hotel or a pension. In 1936, the building was bought by Filip Johann, between 1948 and 1971 it was the home of Waldschlössl sanatorium, and afterwards, the later owners (families Stiasny and Mohorn) used it as their own place.
When reorganising the garden, we had our own first-hand experience about the exciting history of Waldschlössl. A 150 years-old oak tree was cut down, most of its branches were already withered. At the cutting line in the tree, discolourations could be seen. A neighbouring farmer from Geyerhof told us the reason why. In the very last days of the WWII (May of 1945), the belligerent troops battled for several days in the area and a lot of buildings were burnt down. According to the local farmers, trees of this area are not very welcome by lumber mills as grenade fragments immediately ruin saw plates. Discolourations of the oak were caused by these grenade fragments. As we really could not believe the story, we tried to verify it. Annual rings of the tree confirmed the truth, discolourings date back to somewhere between 1935 and 1945.