Madrid (In the center of Spain, the third largest city in the European Union After London and Berlin) 9.7 million visitors

   Art enthusiasts flock to the famous Prado, Thyssen-Bornemisza and Reina Sofia museums. Families enjoy boating in Retiro Park and visiting the zoo and the amusement park in Casa de Campo. After eating paella and tapas and watching flamenco, night owls can dance at clubs that are open until dawn. Strolling through Madrid is a great way to see the lavish Royal Palace, the 16th-century Puerta del Sol (Sun's Gate) marking the center of Spain, the old Moorish quarter of Moreria and much more.