The Palace can be visited
Wimpfen Palace

The Imperial Palace of Wimpfen, a former Staufer residence, is on a mountain spur above the Neckar in Bad Wimpfen. With a length of 215 meters and a width of up to 88 meters, it was the largest of its kind in Germany.
History+
Construction of the palace began in the mid-12th century under Frederick I Barbarossa. After a construction halt around 1190 or at the latest by 1197, building resumed under Frederick II from 1217, possibly continuing under Henry (VII.). Around 1320/22, the palace suffered damage and was subsequently rarely used by the monarchy. It merged with the adjacent town to the west and now forms the castle quarter.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: https://commons.wikimedia.org/wiki/File:Wimpfen-roterturm-befest.jpg
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: 49.2299, 9.1658