Speculation over the existence of a “southern land” is not confirmed until the early 1820s when British and American commercial operators and British and Russian national expeditions begin exploring the Antarctic Peninsula region and other areas south of the Antarctic Circle. Not until 1840 it is established that Antarctica is indeed a continent and not just a group of islands. Several exploration “firsts” are achieved in the early 20th century. Following World War II, there is an upsurge in scientific research on the continent. A number of countries set up year-round research stations on Antarctica. Seven countries make territorial claims, but no other country recognizes these claims. In order to form a legal framework for the activities of nations on the continent, an Antarctic Treaty is negotiated that neither denies nor gives recognition to existing territorial claims; signed in 1959, it enters into force in 1961.