Geneva (Genève in French) is the capital of the Swiss canton of Geneva and the second most populous city in Switzerland. It lies in the French-speaking part of Switzerland on the shores of the lake Geneva. Geneva is a worldwide centre for diplomacy and international cooperation and is host for a number of international organisations: the European headquarters of UNO and other agencies of the UN, the ITU, WIPO. The European Organization for Nuclear Research (CERN), the world's largest particle physics laboratory, is situated in the northwest suburbs of Geneva. Geneva originated as a fortress in Roman empire and developed over the centuries as an independent city. Geneva became first associated with Swiss federation in the early 16th century, when it formed a union with Bern and Fribourg. Geneva was finally admitted to the Swiss federation in 1815.