The Castle can be visited
Seehof Castle

Seehof Palace in Memmelsdorf, near Bamberg in Bavaria, is a former summer residence of the Prince-Bishops of Bamberg. The complex, now part of the municipality of Memmelsdorf, has a once magnificent Rococo garden.
History+
The origins of the complex date back to the 15th century, when a hunting lodge stood on this site. The current four-winged palace building with its corner towers was constructed from 1687 to 1696 under Prince-Bishop Marquard Sebastian Schenk von Stauffenberg, based on plans by Antonio Petrini. It is therefore also known as Marquardsburg. Under Prince-Bishop Lothar Franz von Schönborn, the garden was laid out to its current size and equipped with fountains, wells, and a hedge theater.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Mobile Geschichte
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: 49.9269, 10.9478