Antarctica is the continent at the extreme southern latitudes of the Earth, containing the South Pole. It is surrounded by the Southern Ocean and divided in two by the Transantarctic Mountains. On average, it is the coldest, driest, windiest, and highest of all the continents. Although it is 98% covered in ice, because there is little precipitation, the entire continent is technically a desert and is thus the largest desert in the world. Cold-adapted plants and animals, including penguins, fur seals, mosses, lichens, and many types of algae live on the continent. Although myths and speculation about a Terra Australis ("Southern Land") go back to antiquity, the first sighting of the continent is commonly accepted to have occurred in 1821 by the Russian expedition of Mikhail Lazarev and Fabian Gottlieb von Bellingshausen. Antarctica is not under the political sovereignty of any nation, although seven countries ( Argentina, Australia, Chile, France, New Zealand, Norway and the United Kingdom) maintain territorial claims, which are not recognized by other countries. Human activity on the continent is regulated by the Antarctic Treaty, which was signed in 1959 by 12 countries and prohibits any military activity, supports scientific research, and protects the continent's ecozone.