Reitnau Castle is located in the area of the village of Stambach, in the municipality of Grafendorf near Hartberg. Around 1160, Seifried von Kranichberg had a farm built, which came into the possession of the Counts of Stubenberg in 1309. At the beginning of the 14th century, the Reuter family converted the farm into a small moated castle.
When the Hungarians invaded in 1605, there was major damage to the castle and manor. In 1610 Rudolf von Wurmbrand had the castle rebuilt and enlarged. In 1618 the work was completed. In the 18th century the castle was given its present form.
The castle has been owned by the Lenz family since 1939