The Castle Theatre in Ballenstedt, which opened in 1788, is the oldest working theatre in the state of Saxony-Anhalt. For many years, it was the domain of the composer Carl Christian Agthe (1762-1797). Highlights in the theatre history were definitely the performance of the opera "Undine" under the direction of the composer Albert Lortzing himself (1846) and the guest performance of the singer Joseph Tichatschek in "Tannhaeuser" (1847/48).

The theatre building in its classicist style is situated in front of the castle complex and together they are the landmark of the former residential town of Ballenstedt. The interior of the theatre was carefully restored in recent years and regained its reputation as a gem of theatre architecture towards the end of the 18th century. Today, the theatre has room for more than 350 spectators