Tierra Del Fuego (Sp., "Land of Fire"), a group of islands off the S. extremity of South America, between lat. 52° 40' and 56° S., and lon. 63° 40' and 75° W. It is separated from the mainland by the straits of Magellan, and has the Pacific ocean on the west and the Atlantic on the east, while the E. and W. limits of these seas are supposed to meet at Cape Horn, its S. extremity. The group comprises numerous small islands, of which Cape Horn is the most remarkable; the large island Tier-ra del Fuego proper, of very irregular shape and nearly 300 m. long E. and W.; the islands of Navarin and Hoste to the south, separated from the last named by the Beagle channel; and Dawson, Clarence, and Desolation islands to the west. All these islands are deeply indented. They are mountainous, and many of the peaks are more than 5,000 ft. high, while the highest, Mt. Sarmiento, is about 6,900 ft. The limit of perpetual snow is about 4,000 ft. The soil is generally a swampy peat, and to the height of 1,500 ft. is covered with forests of beech. The geological formation is principally clay slate, greenstone, and granite. The climate is one of the worst in the world; storms, sudden gusts of wind, rain, snow, and mist constantly succeed each other.

The gigantic seaweed ma-crocystis pyrifera is common on the coasts and in the straits, and affords shelter for innumerable shell fish, without which the natives would find it extremely difficult to subsist. Deer, guanacos, foxes, sea otters, mice, bats, and a few other animals are found, and birds, particularly sea fowl, are numerous. The natives are of the same race as the Patagoni-ans, but smaller, and those of the S. E. portion of the group are short, ill made, and ill looking. Their clothing consists entirely of guanaco or seal skin. Their huts, generally built close to the shore in some sheltered spot, are conical, made of branches or small trees stuck in the earth, 7 or 8 ft. in diameter and 4 or 5 ft. in height, with a small hole for a door. - Tierra del Fuego was discovered by Magalhaens in 1520, and received its name from the numerous fires seen during the night along the shore. (See Magellan, Steaits of).