Fort de Joux

Fort de Joux - Credit: Wikimedia Commons

The Fort de Joux () or Château de Joux () 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. Read more on Wikipedia

type: military installation
date from: 11th century
official website: http://www.chateaudejoux.com/

Source: en.wikipedia.org