To be privately owned
Großfurra Castle

Built in the 11th century by the Thuringian Landgraves, Burg Großfurra served to control the Wipper Valley. It stands in what is now the Großfurra district of Sondershausen.
History+
The first documented mention of the castle occurred in 1198, when it was owned by the noble family von Furra. This family became vassals of the Margraves of Meissen in 1249 and later, in 1276, were referred to as vassals of the Honsteiners. After the extinction of the von Furra family in 1332, the castle was divided among various noble families. From 1425, the von Wurmb family gradually acquired all parts of the castle and shaped its destiny for over 500 years. During the Peasants' War in 1525/26, rebels expelled the von Wurmb family, who, however, returned after the suppression. The castle largely survived the plague, wars, and numerous alterations until 1945. In April 1945, the keep was hit by American artillery fire.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Roland Neubert, Halle (Saale)
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 51.3923, 10.7977