The Citadel of Besançon is a 17th-century fortress in Franche-Comté, France. It is one of the finest masterpieces of military architecture designed by Sébastien Le Prestre de Vauban. The Citadel occupies 11 hectares on Mount Saint-Etienne, one of the seven hills that protect Besançon, the capital of Franche-Comté. Mount Saint-Etienne occupies the neck of an oxbow formed by the river Doubs, giving the site a strategic importance that Julius Caesar recognised as early as 58 BC. The Citadel overlooks the old quarter of the city, which is located within the oxbow, and has views of the city and its surroundings.
The fortification is well preserved. Today it is an important tourist site due both to its own characteristics and because it is the site of several museums.
Wikipedia https://en.wikipedia.org/wiki/Citadel_of_Besançon
Address 99A Rue des Fusillés de la Résistance, Besançon 25000, France
Coordinates 47°13'48.693" N 6°2'0.922" E