Penal colony of New Caledonia
New Caledonia, France · built 1864
The penal colony of New Caledonia was a penitentiary establishment which was in operation from 1864 to 1924 on the southwest Pacific islands of New Caledonia. Many French prisoners from mainland France (approximately 21, 000) were deported there. Divided into three categories, these convicts could hope to be released without obtaining a return to mainland France.
Prison data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).