Vienna is Austria's capital, with a population of round about 1.8 million (2.6 million within the metropolitan area) more than 20% of Austria's population, and its cultural, economic, and political centre. It is the 7th-largest city by population within city limits in the European Union and the second largest German-speaking city after Berlin. Vienna is host to many major international organisations, including the United Nations and OPEC. The city is situated in the east of Austria and close to the borders of the Czech Republic, Slovakia, and Hungary. These regions work together in the so called “Centrope” region. Along with nearby Bratislava, Vienna forms a twin-city metropolitan area with 3 million inhabitants.