The Castle can be visited
Ravensberg Castle

Ravensberg Castle, a partially preserved hilltop castle, is a landmark in northeastern North Rhine-Westphalia and the namesake of the County of Ravensberg. It stands on a hill south of Borgholzhausen in the Teutoburg Forest.
History+
Around 1080, Hermann (II.) von Calvelage had Ravensberg Castle built, which served as the ancestral seat of the Counts of Ravensberg until 1346. The complex consisted of an outer and an inner bailey, surrounded by a curtain wall and a dry moat. A gatehouse with a drawbridge and zwinger provided access. After the death of the last local count in 1346, the castle passed to the House of Jülich-Kleve-Berg and later to the Hohenzollerns. During the Thirty Years' War, it changed hands multiple times, with the keep being renovated in 1646. After the last garrison withdrew in 1662, the castle was largely destroyed in 1673 by troops of Prince-Bishop Christoph Bernhard von Galen of Münster.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.zeche.org/
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: 52.0829, 8.2974