Budapest is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second largest city on the Danube river. The city has an estimated population of 1,752,286 over a land area of about 525 square kilometres. Budapest, which is both a city and municipality, forms the centre of the Budapest metropolitan area, which has an area of 7,626 square kilometres and a population of 3,303,786.