Lisbon has 544,851 inhabitants within the administrative center on the area of only 100.05 km2 Administratively defined cities that exist in the vicinity of the capital are in fact part of the metropolitan perimeter of Lisbon. The urban area has a population of 2,666,000 inhabitants, being the eleventh largest urban area in the European Union. The whole metropolis of Lisbon (metropolitan area) has about 3 million inhabitants. According to official government data, the Lisbon metropolitan area has 3,643,876 inhabitants. Other sources also show a similar number, according to the Organisation for Economic Co-operation and Development – 2,797,612 inhabitants; according to the Department of Economic and Social Affairs of the United Nations – 2,890,000; according to the European Statistical Office Eurostat – 2,839,908; according to the Brookings Institution has 2,968,600 inhabitants.