Fort de Joux
La Cluse-et-Mijoux, France
The Fort de Joux (French pronunciation: [f d u]) or Château de Joux (French pronunciation: [ato d u]) is a castle, later transformed into a fort, located in La Cluse-et-Mijoux in the Doubs department in the Jura Mountains of France. It commands the mountain pass Cluse de Pontarlier.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).