Zaragoza, also called Saragossa is the capital city of the Zaragoza province and of the autonomous community of Aragon, Spain. It lies by the Ebro river and its tributaries, the Huerva and the Gállego, roughly in the center of both Aragon and the Ebro basin. On 1 September 2010 the population of the city of Zaragoza was 701,090, within its administrative limits on a land area of, ranking fifth in Spain. It is the 32nd most populous municipality in the European Union. The population of the metropolitan area was estimated in 2006 at 783,763 inhabitants. The municipality is home to more than 50 percent of the Aragonese population. The city lies at an elevation of above sea level. Zaragoza hosted Expo 2008 in the summer of 2008, a worlds fair on water and sustainable development. It was also a candidate for the European Capital of Culture in 2012. The city is famous for its folklore, local gastronomy, and landmarks such as the Basílica del Pilar, La Seo Cathedral and the Aljafería Palace. Together with La Seo and the Aljafería, several other buildings form part of the Mudéjar Architecture of Aragon which is a UNESCO World Heritage Site. The Fiestas del Pilar are among the most celebrated festivals in Spain.