To be privately owned
Château d'Entrechaux

The ruined Château d'Entrechaux is situated on a rocky outcrop above the village of Entrechaux in the French department of Vaucluse.
History+
The origins of the Château d'Entrechaux date back to the 10th or 11th centuries, originally comprising two separate castle complexes. As early as around 900, the Bishops of Vaison began construction of the so-called “Small Castle,” which included a fortified chapel dedicated to Saint Quenin and a cistern carved into the rock. During a period of conflict with the Counts of Toulouse, the bishops shared this complex with the local village lord.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Hervé Rebours
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: 44.2192, 5.1374