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.

A coffer in architecture is a series of sunken panels in the shape of a square, rectangle, or octagon in a ceiling, soffit or vault. A series of these sunken panels was often used as decoration for a ceiling or a vault, also called caissons ("boxes"), or lacunaria, so that a coffered ceiling can be called a lacunar ceiling: the strength of the structure is in the framework of the coffers.