Porto (Portuguese pronunciation: [ˈpoɾtu]), also known as Oporto in English, is Portugal's second city and the capital of Norteregion. It is, along with Lisbon, one of Portugal's two global cities. The city is located in the estuary of the Douro river, in northern Portugal. Being the largest city in the region, it is considered its economic and cultural heart. With an estimated population of about 220,000 (est.2008), it lies at the centre of the political Greater Metropolitan Area of Porto, with a population of slightly more than 1.7 million (est. 2008), and is the main agglomeration of northern Portugal.