Ile du Diable, Devil's Island, off the coast of French Guiana, is one of the three Iles du Salut (Islands of Salvation or Health), so named because they provided a more healthy environment than the mainland for the French gold seekers of the 1760's. The other two are Ile St. Joseph and Ile Royale, separated from Devil's Island by a vicious tide. In later years, Ile du Diable, became part of the prison system developed in French Guiana. Other locations were on the mainland, and the other two islands, but over time, the entire penal colony was called Devil's Island.