Home to one of the world's most notorious prisons, Devil's Island is part of the Îles du Salut chain, which translates—ironically—as the Islands of Salvation. The name's origin is because the islands were a refuge for missionaries who traveled to them when plagues broke out on the mainland. Located 11 kilometers (6.8 miles) off the coast of French Guiana, the chain is volcanic in origin and includes Devil's Island, Royal Island and St. Joseph Island. All were part of the infamous penal colony, where French political prisoners and other criminals were sentenced to hard labor during the 19th and early 20th centuries. Each island prison had a special purpose: Devil's Island was for political prisoners, Royal Island was for the general population and St. Joseph Island was for the worst of the worst, housing the solitary confinement facilities. During the heyday of the penal colony, the bodies of dead prisoners were dumped into the sea to feed the sharks. Although sharks are much rarer these days, the islands are home to abundant wildlife, including green-winged macaws, capuchin monkeys and sea turtles.