The Weissenfels Princely House was built from 1673 onwards by order of Duke August of Saxony-Weissenfels by Johann Moritz Richter, the master builder of Neu-Augustusburg Castle. It served primarily as the official residence of particularly high-ranking court officials. The building extends over two and a half floors and three wings. The representative facade is decorated and structured by various decorative elements. For example, pillars, an oriel-like projection in the center of the building and a lateral passage portal. Above this are figures representing Minerva and Mercury. Inside the princely house there are numerous stucco decorations. The central hall of the second floor is particularly richly decorated. Here there is a nine-panel ceiling, modeled around 1680 on the ceiling in the Banqueting House of London's Whitehall Palace. In the center of the ceiling is a painted representation of Hercules as the ruler of war and peace. In the remaining panels are representations of the four seasons and the four elements. The floral and ornamental stuccowork of the ceiling and the wall partition is probably by Giovanni Caroveri. After the extinction of the ducal line of Saxony-Weißenfels, the house was used for many purposes, including, together with the adjoining buildings, as a silk factory. Today it houses the Weissenfels registry office, which was voted one of the 10 most beautiful in all of Germany. On the first floor there is a restaurant.