Tierra del Fuego (tyĕˈrä dĕl fwāˈgō) [key], [Span., = land of fire], archipelago, 28,476 sq mi (73,753 sq km), off S South America, separated from the mainland by the Strait of Magellan. It consists of one large island (sometimes called simply Tierra del Fuego), five medium-sized islands, and numerous small islands, islets, and rocks separated by many inlets and channels. The Andes extend through the western part, and the plateau of Patagonia continues into the eastern section. The coastal plains are bleak, with frequent high winds and much rainfall, while the inland areas and the mountains are often very cold. Tierra del Fuego is divided into two sections, the eastern part belonging to Argentina (the territory of Tierra del Fuego) and the larger western part to Chile (a part of Magallanes prov.). The economy is based on the exploitation of petroleum and tourism; there is some light industry. Sheep raising, once important, is now less so. Tierra del Fuego was discovered by Ferdinand Magellan in 1520 but was not well surveyed until the early 19th cent. The introduction of sheep farming and the discovery of gold in the 1880s led to European, Argentine, and Chilean immigration. The aboriginal peoples of Tierra del Fuego (the Onas, Alakalufs, and Yahgans) were gradually killed off by disease.