Holy See
Although the Holy See is sometimes metonymically referred to as the "Vatican", the Vatican City State was distinctively established with the Lateran Treaty (1929) between the Holy See and Italy to ensure the temporal, diplomatic, and spiritual independence of the Papacy. As such, ambassadors are officially accredited to the Holy See and not the Vatican City State. Conversely, Papal nuncios to states and international organisations are recognised as representing the Holy See and the integrity of the Catholic Church along with its 1.3 billion members, not the Vatican City State, as prescribed also in the Canon law of the Catholic Church (1983). The "Holy See" thus refers to the See of Rome viewed as the central government of the Catholic Church. The Catholic Church, in turn, is the largest non-government provider of education and health care in the world, while the diplomatic status of the Holy See facilitates the access of its vast international network of charities.
Vatican Observatory
Father Angelo Secchi SJ relocated the College Observatory to the top of Sant'Ignazio di Loyola a Campo Marzio (Church of St. Ignatius in Rome). In 1870, with the capture of Rome, the College Observatory fell into the hands of the Italian Government. Out of respect for his work, however, Father Secchi was permitted to continue using the Observatory. After Secchi's death in 1878 the Observatory was nationalized by the Italian government and renamed the "Regio Osservatorio al Collegio Romano" ("Royal Observatory at the Roman College"), ending astronomical research in the Vatican.
In 1891, however, Pope Leo XIII issued a Motu Proprio re-founding the "Specola Vaticana" (Vatican Observatory) and a new observatory was built on the walls at the edge of the Vatican. The new Vatican Observatory remained there for the next forty years.
By the 1930s, the smoke and sky-glow of the city had made it impossible to conduct useful observations in Rome. Pope Pius XI relocated the Observatory to Castel Gandolfo, which is southeast of Rome. By 1961, the same problems with light pollution made observing difficult at Castel Gandolfo. The Observatory then established the Vatican Observatory Research Group, with offices at the Steward Observatory of the University of Arizona in Tucson, Arizona.