Lisbon is the capital and the largest city of Portugal, with an estimated population of 505,526 within its administrative limits in an area of 100.05 km2. Lisbon's urban area extends beyond the city's administrative limits with a population of around 2.8 million people, being the 10th-most populous urban area in the European Union. About 3 million people live in the Lisbon metropolitan area, which represents approximately 27% of the country's population. It is mainland Europe's westernmost capital city and the only one along the Atlantic coast. Lisbon lies in the western Iberian Peninsula on the Atlantic Ocean and the River Tagus. The westernmost portions of its metro area, the Portuguese Riviera, form the westernmost point of Continental Europe, culminating at Cabo da Roca.