Château D'If Fortress On The Island Of If, Frioul Archipelago, Bay Of Marseille, Mediterranean Sea, France

After his assassination in Cairo in 1800, the embalmed body of general Jean Baptiste Kléber was repatriated to France. Napoleon, fearing his tomb would become a symbol to Republicanism, ordered it to stay at the château. It remained there for 18 years until Louis XVIII granted a proper burial in his native Strasbourg.
Prison
The isolated location and dangerous offshore currents of the Château d'If made it an ideal escape-proof prison, very much like the island of Alcatraz in California was in more modern times. Its use as a dumping ground for political and religious detainees soon made it one of the most feared and notorious jails in France. Over 3,500 Huguenots (French Protestants) were sent to If, as was Gaston Crémieux, a leader of the Paris Commune, who was shot there in 1871.