The Castle can be visited
New Castle Eremitage

The New Palace Eremitage, also known as the Sun Temple, is a Rococo palace in Bayreuth, Bavaria. It forms the architectural centerpiece of the Eremitage park complex and has a gilded quadriga on the central section.
History+
The origins of the Eremitage date back to 1616 when the Margraves of Bayreuth acquired a forest area. From 1715, Margrave Georg Wilhelm had a small summer palace and other buildings constructed for a courtly hermitage. The complex was inaugurated in 1719 and completed by 1722. Under Margrave Friedrich and his wife Wilhelmine, the Eremitage underwent expansion from 1735.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Jürgen Grösel
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: 49.9481, 11.6235