4. London, England
Source: Iconosquare
London is one of the largest cities in the United Kingdom. It’s City of London core is also one of the oldest and has medieval aged buildings. Tourism is important here, as many come to see the Queen’s Buckingham Palace or to visit Westminster. However, it is also an important government and financial sector for the country. It’s a center for fashion, education and commerce. London had 16.8 million visitors in 2013.