English: The Pantheon, or Pantheum, is one of the greatest extant Architectural works built by the ancient Roman Empire, standing in the Piazza della Rotonda in the city of Rome, Italy. Constructed between 113 and 125 AD, during the reigns of Trajan and Hadrian, the building was built on the site of an earlier temple built by Marcus Agrippa during the reign of Augustus. The building is constructed of brick, with a front portico consisting of 16 granite Corinthian columns, which support a large, sparingly detailed stone architrave, bearing the words “M Agrippa L F Cos Tertium Fecit,” stating that Marcus Agrippa made this building, which led to centuries of misconceptions about its origins; it is now widely accepted that the architrave and portico were reused from the previous Pantheon. Above the architrave is a stone pediment, which once had an ornate bronze relief affixed to it, long since lost. The orthogonal portico is connected to the cylindrical cella by a rectangular vestibule. The interior of the structure is famous for having intact ancient details, with the most notable being the widest clear-span dome built before the Renaissance, built of concrete, coffered on the interior and faced with brick on the exterior. In the center of the dome is the oculus, which is open to the sky, allowing light and air into the space. The building originally served as a large Roman temple, with statues to the deities of the polytheistic religion being located in niches around the perimeter of the interior. In 609 AD, after the rise and adoption of Christianity across the Roman Empire, the building was given by Emperor Phocas to the Pope, and subsequently converted into a church. The usage of the building as a church led to the loss of many ancient Roman features, sculptures, and artwork, but preserved the structure from demolition by neglect or being used as a quarry for building materials. However, over the centuries, the building was altered and details were lost to construction projects, as well as the whims of emperors, popes, and artifact collectors. The building attained its current appearance in the 19th Century with the removal of later additions.