Devil's Island, part of a three-island chain called Îles du Salut, in French Guiana, was home to one of the most infamous—and impregnable—prisons of the 19th and 20th centuries. Opened in 1852, it received worldwide renown in the mid-1890s when French military captain Alfred Dreyfus was sentenced to life imprisonment after being wrongly convicted of selling military secrets to Germany. Although Dreyfus's sentence was commuted after five years, more than 80,000 political prisoners and hardened criminals endured years of mistreatment and abuse among disease-ridden conditions. Few were able to escape, though Henri Charrière, author of the book Papillon, allegedly succeeded by filling sacks with coconuts in order to float to the mainland. The prison was officially closed in 1953. In 1965, the French government transferred responsibility of the island to the Guiana Space Centre, and in recent years, tourism facilities have been added. Devil's Island and its two smaller neighboring islands receive more than 50,000 visitors each year.