Barcelona is the capital and the most populous city of Catalonia, and the second largest city in Spain, with a population of 1,621,537, climbing to 4,200,000 for the metropolitan area.
The main tra...
Berlin is the capital city of Germany, and one of the sixteen states of Germany. With a population of 3.4 million it is also Germany's largest city.
Berlin's urban transport development plan ("Stad...