Barcelona capital of the autonomous community of Catalonia and the second largest city in the country, with a population of 1,620,943 within its administrative limits. The urban area of Barcelona extends beyond the administrative city limits with a population of around 4.5 million, 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 the largest metropolis on the Mediterranean Sea. 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 metres. Founded as a Roman city, Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona continued to be an important city in the Crown of Aragon. Besieged several times during its history, Barcelona has aSee More