The remains of the Castle can be visited
Ellar Castle (Ruin)

The Ellar ruin, once a strategically important fortification, stands in Waldbrunn, Hesse. Designed as a rectangular complex, its remains are medieval architecture.
History+
The origins of Ellar Castle date back to the late 13th century, when it was probably built by the Counts of Diez to secure important imperial roads. A first documentary mention occurred in 1323, when a burgrave of Ellar was named in the entourage of Count Emicho of Nassau Hadamar. In 1368, the castle passed into the possession of the County of Katzenelnbogen as part of a dowry, a transfer confirmed by Emperor Charles IV as an immediate imperial fief. During the Mainz Diocesan Feud, Ellar served as an important base for the Counts of Katzenelnbogen against the County of Sayn.
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: 50.5084, 8.0937