Vienna is the capital and largest city of Austria, and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.757 million (2.4 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. Until the beginning of the 20th century it was the largest German-speaking city in the world, and before the splitting of the Austro-Hungarian Empire in World War I the city had 2 million inhabitants. Today it is the second only to Berlin in German speakers. Vienna is host to many major international organizations, including the United Nations and OPEC. The city lies in the east of Austria and is close to the borders of the Czech Republic, Slovakia, and Hungary. These regions work together in a European Centrope border region. Along with nearby Bratislava, Vienna forms a metropolitan region with 3 million inhabitants. In 2001, the city centre was designated a UNESCO World Heritage Site.
The city was ranked 1st globally for its culture of innovation in 2007 and 2008, and fifth globally (out of 256 cities) in the 2011 Innovation Cities Index, which analyzed 162 indicators in covering three areas: culture, infrastructure, and markets. Vienna regularly hosts urban planning conferences and is often used as a case study by urban planners. Between 2005 and 2010, Vienna was the world's number one destination for international congresses and conventions. It attracts about five million tourists a year.