Switzerland, officially the Swiss Confederation, is a country situated in the confluence of Western, Central, and Southern Europe. It is a federal republic composed of 26 cantons, with federal authorities based in Bern. Switzerland is a landlocked country bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. It is geographically divided among the Swiss Plateau, the Alps, and the Jura, spanning a total area of 41,285 km2 (15,940 sq mi), and land area of 39,997 km2 (15,443 sq mi). While the Alps occupy the greater part of the territory, the Swiss population of approximately 8.5 million is concentrated mostly on the plateau, where the largest cities are located, among them the three economic centres of Zürich, Geneva and Basel, where multiple international organisations and the only three international airports of Switzerland are domiciled.