The two-winged Renaissance castle dates back to 1588. Further renovations were commissioned around 1670 by the canons Siegbert von Geilenkirchen and Thomas von Kandlberg. It is characterized by an arcaded walkway facing the courtyard. These arcades were enclosed by outbuildings until the renovation.
The rooms on the upper floor also served as the official residence of the caretaker – and thus of the courts – for a long time. The Knights of Kast occupied the castle as a summer residence.
The dilapidated castle was finally purchased by the municipality of Sierning in 1969 and renovated by the Traunviertel Cultural Association and the town of Sierning.
An annex was added to the building, which houses the Sierning municipal office. Following the revitalization of the castle courtyard and the installation of state-of-the-art infrastructure, including a new castle café, it is now possible to host any event. The flagship events are the summer arts and crafts market with up to 10,000 visitors, the Sierning Advent with its Advent village in the castle courtyard, and the Guard Festival. Numerous cultural events and concerts take place throughout the year, both in the castle and in the covered courtyard.