Listed as a UNESCO World Heritage Site, Vauban's 17th century masterpiece, the Besançon Citadel, is considered to be one of the finest in France. The fortifications cover 11 hectares and lie more than 100 metres above the old town sitting in a loop of the River Doubs. The site is encircled by ramparts topped by walkways and punctuated with watchtowers and bartizans. The walls are up to 20 metres high and 5 to 6 metres thick. The Citadel offers visitors spectacular views over the old town of Besançon and the surrounding hills.

The Citadel houses various museums the largest dealing with the origins and development of Nazism, the war and the Vichy regime, the concentration camps, the French Resistance movement and the Liberation. All are covered using photographs, texts and original documents. Awarded "Musée de France" status by the French government, the choice of the Citadel for its location is highly symbolic as 100 resistance fighters were executed by firing squads here during the Occupation. A memorial to them stands outside the Museum.