The Mausoleum of Hadrian is a towering cylindrical building in Parco Adriano, Rome. It was initially commissioned by the Roman Emperor Hadrian as a mausoleum for himself and his family. The building was later used by the popes as a fortress and castle, and is now a museum. The structure was once the tallest building in Rome.

One of the most enchanting old streets of the city, Via del Governo Vecchio will lead you to the next step of your itinerary.

Piazza Navona is a public open space in Rome. It is built on the site of the Stadium of Domitian, built in the 1st century AD, and follows the form of the open space of the stadium. The ancient Romans went there to watch the agones ("games"), and hence it was known as "Circus Agonalis" ("competition arena"). It is believed that over time the name changed to in avone to navone and eventually to navona.

The Pantheon is a former Roman temple and since the year 609 a Catholic church (Basilica di Santa Maria ad Martyres or Basilica of St. Mary and the Martyrs), in Rome, Italy, on the site of an earlier temple commissioned by Marcus Agrippa during the reign of Augustus (27 BC – 14 AD).

At the centre of the piazza, backing onto the Inquisition convent, is the 1667 Elephant and Obelisk by Bernini. This obelisk was excavated in the cloister and came from the Iseum. The elephant was known as "il pulcin della Minerva", or "porcino", from the Roman people's story that - uninspired by elephants - Bernini in fact sculpted a pig.

Largo di Torre Argentina is a square in Rome, Italy, with four Roman Republican temples and the remains of Pompey's Theatre. It is in the ancient Campus Martius. The name of the square comes from the Torre Argentina, which takes its name from the city of Strasbourg whose Latin name was Argentoratum. In 1503, the Papal Master of Ceremonies Johannes Burckardt, who came from Strasbourg and was known as "Argentinus", built in via del Sudario a palace (now at number 44), called Casa del Burcardo, to which the tower is annexed.

The tour will end where it started: in the wonderful Piazza Mattei!

The Basilica of Saint Mary Major or church of Santa Maria Maggiore, is a Major papal basilica as well as one of the Seven Pilgrim Churches of Rome and the largest Catholic Marian church in Rome, Italy. The basilica enshrines the venerated image of Salus Populi Romani, depicting the Blessed Virgin Mary as the health and protectress of the Roman people, which was granted a Canonical coronation by Pope Gregory XVI on 15 August 1838 accompanied by his Papal bull Cælestis Regina. Pursuant to the Lateran Treaty of 1929 between the Holy See and Italy, the Basilica is within Italian territory and not the territory of the Vatican City State. However, the Holy See fully owns the Basilica, and Italy is legally obligated to recognize its full ownership thereof and to concede to it "the immunity granted by International Law to the headquarters of the diplomatic agents of foreign States". In other words, the complex of buildings has a status somewhat similar to a foreign embassy(hop-on hop-off stop)

The Circus Maximus is an ancient Roman chariot-racing stadium and mass entertainment venue in Rome, Italy. In the valley between the Aventine and Palatine hills, it was the first and largest stadium in ancient Rome and its later Empire. It measured 621 m (2,037 ft) in length and 118 m (387 ft) in width and could accommodate over 150,000 spectators. In its fully developed form, it became the model for circuses throughout the Roman Empire. The site is now a public park. (hop-on hop-off stop)

Piazza Venezia is a central hub of Rome, Italy, in which several thoroughfares intersect, including the Via dei Fori Imperiali and the Via del Corso. It takes its name from the Palazzo Venezia, built by the Venetian Cardinal, Pietro Barbo (later Pope Paul II) alongside the church of Saint Mark, the patron saint of Venice. The Palazzo Venezia served as the embassy of the Republic of Venice in Rome. One side of the Piazza is the site of Italy's Tomb of the Unknown Soldier in the Altare della Patria, part of the Monument to Vittorio Emanuele II, first king of Italy. The piazza or square is at the foot of the Capitoline Hill and next to Trajan's Forum. The main artery, the Via di Fori Imperiali begins there and leads past the Roman Forum to the Colosseum. (hop-on hop-off stop)

Vatican City, officially the Vatican City State is an independent city-state and enclave located within Rome, Italy. The Vatican City State, also known simply as the Vatican, became independent from Italy with the Lateran Treaty (1929). With an area of 49 hectares (121 acres) and a population of about 825, it is the smallest state in the world by both area and population. As governed by the Holy See, the Vatican City State is an ecclesiastical or sacerdotal-monarchical state (a type of theocracy) 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 national 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. (hop-on hop-off stop)

The Mausoleum of Hadrian, usually known as Castel Sant'Angelo, is a towering cylindrical building in Parco Adriano, Rome, Italy. It was initially commissioned by the Roman Emperor Hadrian as a mausoleum for himself and his family. The building was later used by the popes as a fortress and castle, and is now a museum. The structure was once the tallest building in Rome. (hop-on hop-off stop)

The Spanish Steps are a set of steps in Rome, Italy, climbing a steep slope between the Piazza di Spagna at the base and Piazza Trinità dei Monti, dominated by the Trinità dei Monti church at the top. The monumental stairway of 135 steps (the slightly elevated drainage system is often mistaken for the first step) was built with French diplomat Étienne Gueffier's bequeathed funds of 20,000 scudi, in 1723–1725, linking the Trinità dei Monti church that was under the patronage of the Bourbon kings of France and the Bourbon Spanish Embassy at the top of the steps to the Holy See in the Palazzo Monaldeschi at the bottom of the steps. The stairway was designed by architects Francesco de Sanctis and Alessandro Specchi. (hop-on hop-off stop)

Piazza Barberini is a large piazza in the centro storico or city center of Rome, Italy and situated on the Quirinal Hill. It was created in the 16th century but many of the surrounding buildings have subsequently been rebuilt. The current appellation was given in 1625 when it was named after the Palazzo Barberini, the substantial Baroque palace built in an elevated position on the south side of the piazza for the Barberini. Originally, there was a large entrance gateway to the palace designed by the Baroque painter and architect Pietro da Cortona on the south east corner of the piazza but this was demolished to make way for the construction of a new road in the 19th century. However, its appearance is known from engravings and early photographs of the piazza. At the centre of the piazza is the Fontana del Tritone or Triton Fountain (1642–3) sculpted by Bernini. (hop-on hop-off stop)

The Trevi Fountain is a fountain in the Trevi district in Rome, Italy, designed by Italian architect Nicola Salvi and completed by Giuseppe Pannini and several others. Standing 26.3 metres (86 ft) high and 49.15 metres (161.3 ft) wide, it is the largest Baroque fountain in the city and one of the most famous fountains in the world. The fountain has appeared in several films, including Roman Holiday (1953), the eponymous Three Coins in the Fountain (1954), Federico Fellini's classic La Dolce Vita (1960),Sabrina Goes to Rome (1998) and The Lizzie McGuire Movie (2003) (hop-on hop-off stop)