Warsaw, officially the Capital City of Warsaw, is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland. Its population is officially estimated at 1.86 million residents within a greater metropolitan area of 3.1 million residents, which makes Warsaw the 6th most-populous city in the European Union. The city area measures 517 km2 and comprises 18 districts, while the metropolitan area covers 6,100 km2.