Palazzo di San Callisto

A Holy See palace on piazza di San Calisto. it.wikipedia records that it houses dicasteries and offices of the Roman Curia and of the Holy See's diplomatic service. Under the Lateran Treaty of 11 February 1929, Italy recognises the Holy See's full ownership of this property (Art. 13; Annex II). Art. 15 states that the property, «benché facenti parte del territorio dello Stato italiano» — although forming part of the territory of the Italian State — enjoys the immunities that international law grants to the headquarters of the diplomatic agents of foreign States. It is on Italian soil and visitors are subject to Italian law. It is not Vatican City and is not described as such here.