The Pantheon is a former Roman temple and, since AD 609, a Catholic church in Rome, Italy. It was built on the site of an earlier temple commissioned by Marcus Agrippa during the reign of Augustus, then after that burnt down, the present building was ordered by the emperor Hadrian and probably dedicated c. AD 126. 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.

Pediments are a form of gable in classical architecture, usually of a triangular shape. Pediments are placed above the horizontal structure of the cornice, or entablature if supported by columns. In ancient architecture, a wide and low triangular pediment typically formed the top element of the portico of a Greek temple, a style continued in Roman temples. But large pediments were rare on other types of building before Renaissance architecture. For symmetric designs, it provides a center point and is often used to add grandness to entrances.