Pontifical Academy of Sciences

The Casina Pio IV (or Villa Pia) is a patrician villa in Vatican City which is now home to the Pontifical Academy of Sciences, the Pontifical Academy of Social Sciences and the Pontifical Academy of St. Thomas Aquinas. The predecessor of the present complex structure was begun in the spring of 1558 by Pope Paul IV in the Vatican Gardens, west of the Cortile del Belvedere. Paul IV commissioned the initial project of the 'Casina del Boschetto', as it was originally called, from an unknown architect; the first mention of the single-storey building can be found on 30 April 1558, and a notice of the following 6 May, says that the Pope spent "two thirds of his time at the Belvedere, where he has begun to build a fountain in the woods". Upon Paul IV's death on 18 August 1559, Pope Pius IV took on the project, which had not yet been completed, and, turning to Pirro Ligorio, improved it. The complex, as it was completed in 1562, comprised an elliptical cortile, two free-standing portals, and the loggia with its fountain. Rich sculptural stuccos, once supplemented by some fifty ancient Roman sculptures, enliven the exterior (illustration). A team of at least six major painters, including Federico Barocci, Federico Zuccari, and Santi di Tito and their assistants, frescoed the interiors.The Casina's rich and at times obscure iconographic programme, of the efficacy of baptism, the primacy of the papacy and the welcomed punitive powers of the Church, seems to have been inspired by Cardinal Charles Borromeo, nephew of Pius IV, who probably had it in mind as the headquarters for the Academy he was about to found, on 20 April 1562, called Accademia Noctes Vaticanae. Graham Smith suggests that the interrelated iconography of the interior frescoes was inspired by Cardinal Marcantonio da Mula. Pope Pius XI, the founder of the current Pontifical Academy of Sciences, made the Casina the Academy's current headquarters in 1936.

The Latinitas Foundation (Latin: Opus Fundatum Latinitas) was an organisation dedicated to furthering the education of Latin and the publication of articles in the language. It was established on 30 June 1976 by Pope Paul VI and was superseded by the Pontifical Academy for Latin (Pontificia Academia Latinitatis) which was established on 10 November 2012 by Pope Benedict XVI.

A pontifical academy is an academic honorary society established by or under the direction of the Holy See. Some were in existence well before they were accepted as "Pontifical."

The Pontifical Academy of Social Sciences (Latin: Pontificia Academia Scientiarum Socialium, or PASS) is a pontifical academy established on 1 January 1994 by Pope John Paul II and is headquartered in the Casina Pio IV in Vatican City. It operates much like other learned societies worldwide, but has the special task of entering into dialogue with the Church. Its scientific activities are organised and focused to promote this dialogue.

The Holy See (Latin: Sancta Sedes, Ecclesiastical Latin: [ˈsaŋkta ˈsedes]; Italian: Santa Sede [ˈsanta ˈsɛːde]), also called the See of Rome, Petrine See or Apostolic See, is the jurisdiction of the Pope in his role as the bishop of Rome. It includes the apostolic episcopal see of the Diocese of Rome, which has ecclesiastical jurisdiction over the Catholic Church and sovereignty over the city-state known as Vatican City. According to Catholic tradition, it was founded in the first century by Saints Peter and Paul and, by virtue of the doctrines of Petrine and papal primacy, is the focal point of full communion for Catholic Christians around the world. As a sovereign entity, the Holy See is headquartered in, operates from, and exercises "exclusive dominion" over the independent Vatican City State enclave in Rome, of which the pope is sovereign. The Holy See is administered by the Roman Curia (Latin for "Roman Court"), which is the central government of the Catholic Church. The Roman Curia includes various dicasteries, comparable to ministries and executive departments, with the Cardinal Secretary of State as its chief administrator. Papal elections are carried out by part of the College of Cardinals. Although the Holy See is sometimes metonymically referred to as the "Vatican", the Vatican City State was distinctively established with the Lateran Treaty of 1929, between the Holy See and Italy, to ensure the temporal, diplomatic, and spiritual independence of the papacy. As such, papal nuncios, who are papal diplomats to states and international organizations, are recognized as representing the Holy See and not the Vatican City State, as prescribed in the Canon law of the Catholic Church. The Holy See is thus 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.The Holy See maintains bilateral diplomatic relations with 183 sovereign states, signs concordats and treaties, and performs multilateral diplomacy with multiple intergovernmental organizations, including the United Nations and its agencies, the Council of Europe, the European Communities, the Organization for Security and Co-operation in Europe, and the Organization of American States.

The geography of Vatican City is unique due to the country's position as an urban, landlocked enclave of Rome, Italy. With an area of 49 ha (121 acres, or 0.19 sq mi), and a border with Italy of 3.5km, it is the world's smallest independent state. Outside the Vatican City, thirteen buildings in Rome and Castel Gandolfo (the pope's summer residence) enjoy extraterritorial rights (one building, the Paul VI Audience Hall, straddles the border, but its Italian portion has extraterritorial rights). The country contains no major natural resources, and no known natural hazards other than those that affect Rome in general, such as earthquakes.

The Mater Ecclesiae Monastery (Latin for 'Mother of the Church') is a monastery in Vatican City. It was founded around 1990 by Pope John Paul II as a monastery for cloistered nuns. Benedict XVI lived there from his resignation in 2013 till his death in 2022.

Vatican City ( (listen)), officially Vatican City State (Italian: Stato della Città del Vaticano; Latin: Status Civitatis Vaticanae), is a landlocked independent city-state, microstate and enclave within Rome, Italy. It became independent from Italy in 1929 with the Lateran Treaty, and it is a distinct territory under "full ownership, exclusive dominion, and sovereign authority and jurisdiction" of the Holy See, itself a sovereign entity of international law, which maintains the city state's temporal, diplomatic, and spiritual independence. With an area of 49 hectares (121 acres) and a 2019 population of about 453, it is the smallest state in the world both by area and population. As governed by the Holy See, Vatican City State is an ecclesiastical or sacerdotal-monarchical state ruled by the Pope who is the bishop of Rome and head of the Catholic Church. The highest state functionaries are all Catholic clergy of various origins. After the Avignon Papacy (1309–1377) the popes have mainly resided at the Apostolic Palace within what is now Vatican City, although at times residing instead in the Quirinal Palace in Rome or elsewhere. The Vatican is also a metonym for the Holy See. The Holy See dates back to early Christianity and is the principal episcopal see of the Catholic Church, which has approximately 1.329 billion baptised Catholics in the world as of 2018 in the Latin Church and 23 Eastern Catholic Churches. The independent state of Vatican City, on the other hand, came into existence on 11 February 1929 by the Lateran Treaty between the Holy See and Italy, which spoke of it as a new creation, not as a vestige of the much larger Papal States (756–1870), which had previously encompassed much of Central Italy. Vatican City contains religious and cultural sites such as St. Peter's Basilica, the Sistine Chapel, and the Vatican Museums. They feature some of the world's most famous paintings and sculptures. The unique economy of Vatican City is supported financially by donations from the faithful, by the sale of postage stamps and souvenirs, fees for admission to museums, and sales of publications. Vatican City has no taxes and items are duty-free.

The Gregorian Tower (Italian: Torre Gregoriana) or Tower of the Winds (Italian: Torre dei Venti) is a square tower and early modern observatory located above the Gallery of Maps, which connects the Villa Belvedere with the Apostolic Palace in Vatican City. The tower was built between 1578 and 1580 to a design by the Bolognese architect Ottaviano Mascherino (who was credited with building the Apostolic Palace) mainly to promote the study of astronomy for the Gregorian Calendar Reform which was commissioned by Pope Gregory XIII and promulgated in 1582. It was then also known as the Tower of Winds. The tower was also called "Specola Astronomica Vaticana", a reference to the Vatican Observatory. Four stages of progressive development have occurred since it was first established. The tower was an edifice of great value for astronomical observations made using a sundial as they provided essential confirmation of the need to reform the Julian calendar.

The Vatican Apostolic Library (Latin: Bibliotheca Apostolica Vaticana, Italian: Biblioteca Apostolica Vaticana), more commonly known as the Vatican Library or informally as the Vat, is the library of the Holy See, located in Vatican City. It was formally established in 1475, although it is much older—it is one of the oldest libraries in the world and contains one of the most significant collections of historical texts. It has 75,000 codices from throughout history, as well as 1.1 million printed books, which include some 8,500 incunabula.The Vatican Library is a research library for history, law, philosophy, science, and theology. The Vatican Library is open to anyone who can document their qualifications and research needs. Photocopies for private study of pages from books published between 1801 and 1990 can be requested in person or by mail. Pope Nicholas V (1447–1455) envisioned a new Rome with extensive public works to lure pilgrims and scholars to the city to begin its transformation. Nicolas wanted to create a "public library" for Rome that was meant to be seen as an institution for humanist scholarship. His death prevented him from carrying out his plan, but his successor Pope Sixtus IV (1471–1484) established what is now known as the Vatican Library. In March 2014, the Vatican Library began an initial four-year project of digitising its collection of manuscripts, to be made available online. The Vatican Apostolic Archive was separated from the library at the beginning of the 17th century; it contains another 150,000 items.

The Vatican Necropolis lies under the Vatican City, at depths varying between 5–12 metres below Saint Peter's Basilica. The Vatican sponsored archaeological excavations (also known by their Italian name scavi) under Saint Peter's in the years 1940–1949 which revealed parts of a necropolis dating to Imperial times. The work was undertaken at the request of Pope Pius XI who wished to be buried as close as possible to Peter the Apostle. It is also home to the Tomb of the Julii, which has been dated to the third or fourth century. The necropolis was not originally one of the Catacombs of Rome, but an open-air cemetery with tombs and mausolea. The Vatican Necropolis is not to be confused with the Vatican grottoes, the latter of which resulted from the construction of St. Peter's Church and is located on the ground level of the old Constantinian basilica.

The popularly named "Tomb of the Julii" (Mausoleum "M") survives in the Vatican Necropolis beneath St. Peter's Basilica. The serendipitous discovery near the crypt has a vaulted ceiling bearing a mosaic depicting Helios (Roman Sol Invictus) with an aureole riding in his chariot, within a framing of rinceaux of vine leaves. The mosaic is dated to the late 3rd century to early 4th century. Other mosaics in this tomb depicting Jonah and the whale, the good shepherd carrying a lamb (the kriophoros motif), and fishermen have encouraged its interpretation as a Christian tomb. This tomb was first discovered in 1574 AD when workmen accidentally broke through the ceiling while conducting some floor alterations in the basilica. The inside was briefly explored and documented before the opening was sealed over once more.