Volcanic in origin, the Juan Fernandez islands are an archipelago located off the coast of Chile in South America. Sparsely inhabited, they are made up of four islands and their surrounding islets; Isla Mas a Tierra (Robinson Crusoe Island), Islote Juananga (Junanga), Isla Santa Clara (Santa Clara) and Isla Mas Afuera (Alexander Selkirk Island). They are mainly known for having been the home of Alexander Selkirk for four years, and may have inspired his novel "Robinson Crusoe". In 1574,they were discovered by the Spanish Sailor Juan Fernandez. During the 17th and 18th centuries they were used as a hideout for pirates and provided a location for a penal colony. In the 19th century, whaleships frequently stopped to reprovision. Fur seals were abundant there and were hunted extensively. As a result the Juan Fernandez Fur Seal was nearly driven to extinction.