The properties of the Holy See are regulated by the 1929 Lateran Treaty signed with the Kingdom of Italy.

Although part of Italian territory, some of them enjoy extraterritoriality similar to those of foreign embassies, including tax exemptions.

[1][2] Nonetheless, those visiting these properties are generally required to follow the immigration rules of Italy.

For example, American seminarians at the Pontifical North American College need an Italian visa, despite residing, and studying, in extraterritorial property of the Holy See.

The Fundamental Accord, signed in 1993, grants property rights and tax exemptions to the Holy See over various Christian holy sites in Israel, but the agreement was never finalized because of diplomatic problems between the Vatican and Israeli governments.