The remains of the Castle can be visited
Arnstein Castle

The castle ruin of Arnstein, ancestral seat of the Lords of Arnstein, rises in the Mansfeld-Südharz district in Saxony-Anhalt. The complex with its palas building has attracted visitors as a “romantic ruin” since the 19th century.
History+
The first documented mention of Arnstein Castle occurred in 1156, when Walther II adopted the castle's name. During this period, the first Romanesque castle complex was built, of which the two eastern round towers and the curtain wall between them still remain today. The Lords of Arnstein, connected by marriage to the Ascanians and Wettins, were among the most influential noble families in Saxony and owned lands in the Harz foreland. Around 1294, Walther IX joined the Teutonic Order and handed over the castle to his brother-in-law Otto von Falkenstein. After the extinction of the Falkenstein family in 1334, the lordship passed to the Counts of Regenstein, who sold it to the Counts of Mansfeld in 1387. Around 1400, the Gothic residential tower-like hall building was erected. After destructions in the Peasants' War, a reconstruction took place around 1530 under Count Hoyer IV, during which the central house was built.
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: 51.6844, 11.4108