100 Francs - Île du Diable

The Île du Diable — Devil's Island — was the most notorious cell of the French penal colony system in Guiana, reserved almost exclusively for political prisoners. Alfred Dreyfus spent four years there beginning in 1895, confined to a stone hut under round-the-clock surveillance following his wrongful conviction for treason. His eventual exoneration in 1906 collapsed public support for the entire colonial penitentiary system, though the camps themselves were not formally closed until 1953.

French Guiana issues collector pieces under French monetary authority without being legal tender in metropolitan France — a jurisdictional quirk that keeps the series largely outside mainstream numismatic circulation.