The Pantheon ( /ˈpænθiːən/ or US /ˈpænθiːɒn/;Latin: Pantheon, from Greek: Πάνθεον, an adjective meaning "to every god") is a building in Rome, Italy, commissioned by Marcus Agrippa as a temple to all the gods of Ancient Rome, and rebuilt by Emperor Hadrian in about 126 AD.

The building is circular 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. The height to the oculus and the diameter of the interior circle are the same, 43.3 metres (142 ft).

It is one of the best preserved of all Roman buildings. It has been in continuous use throughout its history, and since the 7th century, the Pantheon has been used as a Roman Catholic church dedicated to "St. Mary and the Martyrs" but informally known as "Santa Maria della Rotonda." The square in front of the Pantheon is called Piazza della Rotonda.

Rome (/ˈroʊm/; Italian: Roma pronounced [ˈroːma] ( listen); Latin: Rōma) is a city and special comune ("Roma Capitale") in Italy. Rome is the capital of Italy and the capital of Lazio (Latin: Latium). With 2.8 million residents in 1,285.3 km² (496.3 sq mi), it is also the country's largest and most populated comune and fourth-most populous city in the European Union by population within city limits. Between 3.2 and 3.7 million people live in the Rome metropolitan area. The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.

Rome's history spans two and a half thousand years. It was the capital city of the Roman Kingdom, the Roman Republic and the Roman Empire, which was the dominant power in Western Europe and the lands bordering the Mediterranean for over seven hundred years from the 1st century BC until the 7th century AD and the city is regarded as one of the birthplaces of western civilization. Since the 1st century AD Rome has been the seat of the Papacy and, after the end of Byzantine domination, in the 8th century it became the capital of the Papal States, which lasted until 1870. In 1871 Rome became the capital of the Kingdom of Italy, and in 1946 that of the Italian Republic.