The Roman Pantheon

The Pantheon (/ˈpænθiən/ or US /ˈpænθiɒn/;[1] Latin: Pantheon,[nb 1] [pantʰewn] from Greek: Πάνθεον [ἱερόν], an adjective understood as "[temple consecrated] to all gods") is a building in Rome, Italy, commissioned by Marcus Agrippa during the reign of Augustus as a temple to all the gods of ancient Rome, and rebuilt by the emperor Hadrian about 126 AD.[2]

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.[3] The height to the oculus and the diameter of the interior circle are the same, 43.3 metres (142 ft).[4]

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."[5] The square in front of the Pantheon is called Piazza della Rotonda. - http://en.wikipedia.org/wiki/Pantheon,_Rome