The Castle can be visited
Museum
Runkel Castle

Runkel Castle, a high-medieval complex in the town of Runkel, in the Limburg-Weilburg district of Hesse, Germany, stands on a rock above the Lahn river and is known for its construction featuring three keeps.
History+
Runkel Castle was first documented in 1159, though its origins likely date back even further. The Lords of Runkel had it built to secure the Lahn bridge. In 1276, a family dispute led to Siegfried V expelling his cousin Heinrich from the castle. Heinrich subsequently began constructing Schadeck Castle on the opposite side of the Lahn in 1288 as a rival fortress. In the same year, the lordships of Runkel and Westerburg were separated. Dietrich III of Runkel expanded his possessions in 1376 and had a castle built next to the existing one. Through marriage, Dietrich IV of Runkel acquired the County of Wied, whose name his descendants adopted. In 1543, the castle hosted the reformer Melanchthon as a guest.
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: 50.4057, 8.1564