The only UNESCO World Heritage Site that comprises an entire sovereign state is Vatican City.
UNESCO inscribed Vatican City on the World Heritage List in 1984. Unlike most World Heritage properties, which protect a monument, neighborhood, landscape, or archaeological zone within a country, the Vatican listing covers the whole territory of the sovereign Vatican City State.
The site’s importance comes from an exceptional concentration of religious, artistic, architectural, and historical treasures. It includes St Peter’s Basilica and Square, the Vatican Museums, the Sistine Chapel, the Apostolic Palace, and extensive collections associated with the papacy. Michelangelo’s Sistine Chapel ceiling and Last Judgment are among its best-known works.
Vatican City became an independent state through the Lateran Treaty of 1929, signed by the Holy See and the Kingdom of Italy. It is distinct from the Holy See, the institution that represents the Catholic Church in international relations, although the two are closely linked. The city-state is an enclave within Rome and is the world’s smallest sovereign state by area.