Frankfurt am Main, better known simply as Frankfurt, is a city in the German state of Hesse and a fifth largest city in Germany with a population of approximately 733,000 inhabitants. Its urban area, however, has an estimated population of 2.3 million, while the Frankfurt/Rhine-Main metropolitan area has a population of 5.6 million.
Frankfurt is the financial and transport hub of Germany and the largest financial center in continental Europe. In Frankfurt are located in the headquarters of important financial institutions such as the European Central Bank, the German Federal Bank and the Frankfurt Stock Exchange, Deutsche Bank, Commerzbank and DZ Bank.
The city is a unique in Germany listed as one of the Global Alpha cities of the world. In 2011, a Mercer company named Frankfurt as a seventh city in the world's quality of life. According to a cost-of-living survey of The Economist, Frankfurt is the most expensive German city and the 10th most expensive city in the world.