, officially called The Holy See, is the smallest country in the world and is located within a walled area of the Italian capital city of Rome. Its area is only about .17 square miles (.44 square km or 108 acres). Vatican City has a population of about 800, none of whom are native permanent residents. Many more commute into the country for work. The Vatican City officially came into existence in 1929 after the Lateran Treaty with Italy. Its government type is considered ecclesiastical and its chief of state is the Catholic Pope. The Vatican City is not a member of the United Nations by its own choice. For more about the Vatican City's status as an independent country, you might want to read my on the status of the Vatican City/Holy See
For more small countries, take a look at my list of the seventeen smallest countries in the world, all those smaller than 200 square miles (a bit larger than Tulsa, Oklahoma).