What is the smallest country in the world by area?

Vatican City is a walled enclave inside Rome, smaller than many urban parks, and it exists as a sovereign state for a very specific historical reason. For over a thousand years the popes ruled the Papal States across central Italy, but Italian unification absorbed that territory, and from 1870 the pope refused to recognise the loss, remaining inside the Vatican in a stand-off known as the Roman Question. It was settled by the Lateran Treaty of 1929, which created a tiny independent state guaranteeing the papacy's freedom from any other government. Everything that defines a country is compressed into that space: its own post office, its own newspaper, a railway with a single station, the Swiss Guard, and the Vatican Museums, along with St Peter's Basilica and the Sistine Chapel. Citizenship there is not inherited but tied to office, so most passport holders are clergy and guards who hold it only while serving.

Vatican City is the only country whose entire territory is inscribed as a UNESCO World Heritage site.