Vatican City

Yellow mailboxes have become an icon in the landscape of the papal city-state.

An excerpt from the article 21 facts about Vatican City

The Vatican Post Office has operated its postal services and issued its stamps since 1929. Vatican Post’s services are described as among the best in the world. More letters are sent from the Vatican than from any other place in the world (2.5 million letters, 7 million postcards, and about 20.000 parcels per year).