This infographic has been made by Statista (statista.com)

According to this infographic made by Statista (Statista.com) some little European countries are literally crowded by tourists.

It is the case of the Vatican City, which is at the top of this list, followed by Andorra, while in the middle and at the bottom of this list there are other European countries, such as Monaco, Malta, San Marino, Iceland and Cyprus.

How could you explain that tourists crowd these little countries?

Why the Vatican City and Andorra are at the top of this list?

Why so many European countries are in this list?