The remains of the Castle can be visited
Wittekindsburg Castle

The Wittekindsburg castle ruin in the Nettetal is the largest early medieval fortification in Lower Saxony. Once covering an area of approximately 16 hectares.
History+
The origins of the Wittekindsburg date back a long way. The outer ramparts of the core castle, considered the oldest part of the complex, probably date from the time of Charlemagne's Saxon Wars between 772 and 804 AD. Radiocarbon dating of foundations of the main castle confirms its use in the 7th to 9th centuries. However, the castle was abandoned by the end of the 10th century. The complex was first mentioned in writing in 1253. It is not certain whether the name “Wittekindsburg” actually refers to the Saxon prince Widukind. Carl Schuchhardt carried out the first archaeological investigations around 1890.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Jörg Heldt
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: 52.3269, 8.0844