Vienna ( ; German: Wien [viːn];) is the capital of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.7 million (2.4 million within the metropolitan area, more than 25% of Austria's population), and is by far the largest city in Austria, as well as its cultural, economic, and political centre. It is the 10th-largest city by population in the European Union. Vienna is host to many major international organizations, such as the United Nations and OPEC.
Vienna 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, and this region is referred to as Twin City. In 2001, the city centre was designated a UNESCO World Heritage Site.
In a 2005 study of 127 world cities, the Economist Intelligence Unit ranked the city first (in a tie with Vancouver, Canada) for quality of life. This assessment was mirrored by the Mercer Survey in 2009 and 2010. Analytically, the city was ranked 1st globally for a culture of innovation in 2007 and 2008, and 2nd globally after Boston in 2009 from 256 cities on an analysis of 162 indicators in the Innovation Cities Index on a 3-factor score covering culture, infrastructure and markets. As a city, Vienna regularly hosts urban planning conferences and is often used as a case study by urban planners.
The city rates highly in popular opinion-based journalistic rankings from magazines such as Monocle, where it is rated 8th among the "Top 25 Livable Cities" in 2010.