The Castle can be visited
Museum
Geyso Castle (Mansbach)

Geyso Castle in Mansbach, an imposing rectangular building with distinctive gables, looks back on a turbulent history. Originally built on the site of a medieval castle, it now presents itself as an impressive example of Renaissance architecture in Hesse.
History+
The origins of the current castle date back to the 13th century, when a castle stood on this site. This was destroyed around 1280 at the behest of Abbot Bertho IV of Fulda, bringing the town of Mansbach under the feudal rule of the monastery. However, the Mansbach family retained jurisdiction and erected the current Geyso Castle between 1577 and 1578. In 1652, the estate passed to Johann von Geyso, whose grandson Valentin had the castle rebuilt into its present rectangular form in the third quarter of the 17th century. Further alterations in 1878 shaped its current appearance. After 1918, the complex temporarily served as a stud farm.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 50.7818, 9.9142