Defined as a public space in the last years of 15th century, when the city market was transferred there from the Campidoglio, Piazza Navona was transformed into a highly significant example of Baroque Roman architecture and art during the pontificate of Innocent X, who reigned from 1644 until 1655, and whose family palace, the Palazzo Pamphili, faced the piazza. It features important sculptural creations: in the center stands the famous Fontana dei Quattro Fiumi or Fountain of the Four Rivers (1651) by Gian Lorenzo Bernini, topped by the Obelisk of Domitian, brought in pieces from the Circus of Maxentius;[2] the church of Sant'Agnese in Agone by Francesco Borromini, Girolamo Rainaldi, Carlo Rainaldi and others; and the aforementioned Pamphili palace, also by Girolamo Rainaldi, that accommodates the long gallery designed by Borromini and frescoed by Pietro da Cortona.[3]

The fountain at the junction of three roads (tre vie)[3] marks the terminal point[4] of the "modern" Acqua Vergine, the revived Aqua Virgo, one of the aqueducts that supplied water to ancient Rome. In 19 BC, supposedly with the help of a virgin, Roman technicians located a source of pure water some 13 km (8.1 mi) from the city. (This scene is presented on the present fountain's façade.) However, the eventual indirect route of the aqueduct made its length some 22 km (14 mi). This Aqua Virgo led the water into the Baths of Agrippa. It served Rome for more than 400 years

he Papal Basilica of St. Peter in the Vatican (Italian: Basilica Papale di San Pietro in Vaticano), or simply St. Peter's Basilica (Latin: Basilica Sancti Petri), is a church built in the Renaissance style located in Vatican City, the papal enclave which is within the city of Rome. Designed principally by Donato Bramante, Michelangelo, Carlo Maderno and Gian Lorenzo Bernini, St. Peter's is the most renowned work of Renaissance architecture[2] and the largest church in the world.[3] While it is neither the mother church of the Catholic Church nor the cathedral of the Diocese of Rome, St. Peter's is regarded as one of the holiest Catholic shrines. It has been described as "holding a unique position in the Christian world"[4] and as "the greatest of all churches of Christendom

Piazza del Popolo is a large urban square in Rome. The name in modern Italian literally means "People's Square", but historically it derives from the poplars (populus in Latin, pioppo in Italian) after which the church of Santa Maria del Popolo, in the northeast corner of the piazza, takes its name. The piazza lies inside the northern gate in the Aurelian Walls, once the Porta Flaminia of ancient Rome, and now called the Porta del Popolo. This was the starting point of the Via Flaminia, the road to Ariminum (modern-day Rimini) and the most important route to the north. At the same time, before the age of railroads, it was the traveller's first view of Rome upon arrival. For centuries, the Piazza del Popolo was a place for public executions, the last of which took place in 1826.

The Pantheon (UK: /ˈpænθiən/, US: /-ɒn/;[1] Latin: Pantheum,[nb 1] from Greek Πάνθειον Pantheion, "[temple] of all the gods") is a former Roman temple, now a church, in Rome, Italy, on the site of an earlier temple commissioned by Marcus Agrippa during the reign of Augustus (27 BC – 14 AD). It was completed by the emperor Hadrian and probably dedicated about 126 AD. Its date of construction is uncertain, because Hadrian chose not to inscribe the new temple but rather to retain the inscription of Agrippa's older temple, which had burned down.[2] The building is cylindrical with a portico of large granite Corinthian columns (eight in the first rank and two groups of four behind) under a pediment. A rectangular vestibule links the porch to the rotunda, which is under a coffered concrete dome, with a central opening (oculus) to the sky. Almost two thousand years after it was built, the Pantheon's dome is still the world's largest unreinforced concrete dome.[3] The height to the oculus and the diameter of the interior circle are the same, 43 metres (142 ft).[4]

n the middle of the square is the famous Fontana della Barcaccia, dating to the beginning of the baroque period, sculpted by Pietro Bernini and his son, the more famous Gian Lorenzo Bernini. At the right corner of the Spanish Steps rises the house of the English poet John Keats, who lived there until his death in 1821: nowadays it has been changed into a museum dedicated to him and his friend Percy Bysshe Shelley, displaying books and memorabilia of English romanticism. At the left corner there is the Babington's tea room, founded in 1893.

The Roman Forum, also known by its Latin name Forum Romanum (Italian: Foro Romano), is a rectangular forum (plaza) surrounded by the ruins of several important ancient government buildings at the center of the city of Rome. Citizens of the ancient city referred to this space, originally a marketplace, as the Forum Magnum, or simply the Forum. For centuries the Forum was the center of day-to-day life in Rome: the site of triumphal processions and elections; the venue for public speeches, criminal trials, and gladiatorial matches; and the nucleus of commercial affairs. Here statues and monuments commemorated the city's great men. The teeming heart of ancient Rome, it has been called the most celebrated meeting place in the world, and in all history.[1] Located in the small valley between the Palatine and Capitoline Hills, the Forum today is a sprawling ruin of architectural fragments and intermittent archaeological excavations attracting 4.5 million or more sightseers yearly.