Vatican City

Vatican City is a walled state inside Rome with an area of only 0.44 square kilometres. You could walk across it in a few minutes.

Some lists cite 0.49 km² depending on how the area is measured.

Context

The Vatican's independence dates to the Lateran Treaty of 1929, in which Italy recognised the sovereignty of the Holy See over a small enclave on the west bank of the Tiber. Before that, the papacy had lost control of the Papal States during Italian unification, and the pope had remained within the Vatican for decades.

The territory is bounded mostly by old defensive walls, with the open edge at St. Peter's Square, and it has six entrances, only some of which the public can use. Because it is entirely surrounded by Rome, it is an enclave, and it is the smallest fully independent state by both area and population, with a resident population in the hundreds.

The area figure depends on what is included. The commonly cited 0.44 km² covers the state itself, while larger values appear when extraterritorial properties in and around Rome are counted or when different survey boundaries are used. Britannica gives different population estimates in different parts of its own article, a reminder that tiny populations are hard to pin down because many staff commute rather than reside there.