The Antarctic Peninsula is the northernmost part of the mainland of Antarctica, located at the base of the Southern Hemisphere.At the surface, it is the biggest, most prominent peninsula in Antarctica as it extends 1,300 km (810 miles) from a line between Cape Adams (Weddell Sea) and a point on the mainland south of Eklund Islands. Beneath the ice sheet which covers it, the Antarctic Peninsula consists of a string of bedrock islands; these are separated by deep channels whose bottoms lie at depths considerably below current sea level. They are joined together by a grounded ice sheet. Tierra del Fuego, the southernmost tip of South America, lies only about 1,000 km (620 miles) away across the Drake Passage.The Antarctic Peninsula is currently dotted with numerous research stations and nations have made multiple claims of sovereignty. The peninsula is part of disputed and overlapping claims by Argentina, Chile and the United Kingdom. None of these claims have international recognition and, under the Antarctic Treaty System, the respective countries do not attempt to enforce their claims. The British claim is recognised though by Australia, France, New Zealand and Norway. Argentina has the most bases and personnel stationed on the peninsula. The first sighting of Antarctic Peninsula is contested but it apparently occurred in the 1820s. Agreement on this name by the US-ACAN and UK-APC in 1964 resolved a long-standing difference involving use of the American name, Palmer Peninsula, and the British name, Graham Land, for this feature. Graham Land is now restricted to that part of Antarctic Peninsula northward of a line between Cape Jeremy and Cape Agassiz; Palmer Land to the part southward of that line. In Chile, it is oficially referred as O´Higgins Land, after the Chilean patriot and Antarctic visionary. The other Spanish countries call it "Península Antártica", among them is Argentina: it has got more bases and people there than any other nation. The peninsula is highly mountainous, its highest peaks rising to approximately 2,800 metres (9,186 feet). These mountains are considered to be a continuation of the Andes of South America, with a submarine spine connecting the two. Since the peninsula has the mildest climate in Antarctica, the highest concentration of research stations on the continent can be found there, or on the many nearby islands. (Source Wikipedia The Free Encyclopedia)