Barcelona is the capital of Catalonia and the second largest city in Spain, after Madrid, with a population of 1,621,537 within its administrative limits on a land area of 101.4 km2 (39 sq mi). The urban area of Barcelona extends beyond the administrative city limits with a population of between 4,200,000 and 4,500,000 within an area of 803 km2 (310 sq mi), being the sixth-most populous urban area in the European Union after Paris, London, the Ruhr, Madrid and Milan. About five million people live in the Barcelona metropolitan area. It is also Europe's largest metropolis on the Mediterranean Sea. It is the main component of an administrative area of Greater Barcelona, with a population of 3,218,071 in an area of 636 km² (density 5,060 hab/km²). It is located on the Mediterranean coast between the mouths of the rivers Llobregat and Besòs and is bounded to the west by the Serra de Collserola ridge (512 m/1,680 ft).
Barcelona is today one of the world's leading tourist, economic, trade fair/exhibitions and cultural-sports centres, and its influence in commerce, education, entertainment, media, fashion, science, and the arts all contribute to its status as one of the world's major global cities. Indeed, it is a major cultural and economic centre in southwestern Europe (Iberian Peninsula), 26th in the world (after Moscow, before Dubai) and a growing financial centre (Diagonal Mar and Gran Via) Europe's fourth best city for business and fastest improving European city. One of Europe's principal Mediterranean ports can be found here as well as Barcelona international airport, which handles above 34 million passengers per year. It also boasts an extensive motorway network and is a hub of high-speed rail, particularly that which will link Spain with France and the rest of Europe.