Which country has the shortest land border in the world?

Vatican City has the shortest land border in the world, sharing its entire frontier with Italy. The border is only about 3.2 kilometres long and encloses the world’s smallest independent state.

Vatican City is a landlocked enclave completely surrounded by the city of Rome. Its boundary was established by the Lateran Treaty, signed on 11 February 1929 between the Holy See and the Kingdom of Italy. The treaty resolved the long-running dispute over the status of the papacy after the capture of Rome in 1870 and created Vatican City as a sovereign state.

The frontier is partly marked by historic walls, including sections of the Leonine Walls, while St Peter’s Square has a subtle boundary marked by a white line. A common mix-up is to choose Monaco or San Marino: both have short borders, but Monaco’s border with France is about 5.5 kilometres and San Marino’s border with Italy is much longer. Vatican City’s sole international border is with Italy.