Sondershausen Castle was the residence of the Schwarzburg counts, princes and rulers of the small Thuringian state for many centuries.

In addition to historical room settings (e.g. Liebhabertheater, castle chapel, vaults on the Wendelstein), the castle museum houses the Schwarzburg ancestral gallery, various sections on the history of the region and town as well as parts of the Schwarzenburg art collections. A rarity is the Golden Coach, a state coach from the early 18th century. Sondershausen's long musical tradition is also the subject of an exhibition, which includes a number of important musical instruments. Exhibitions of contemporary art are held in the »Gallery in the Castle«.