The Pantheon is the most complete and remarkable of Roman temples and is the crowning achievement of Roman architectural and engineering skill. Dedicated to the seven planetary deities, the Pantheon was built by Hadrian between AD 118 and AD 128 to replace an earlier temple.
An uninspiring outward appearance belies the magnificence of its interior. From a conventional columned porch a circular hall surmounted by a hemispherical dome is entered.
Its pleasing proportions were created by giving the dome an internal height equal to the diameter of the floor (142 ft - 43.2 m). The huge span of the dome, which was not surpassed until modern times, was made possible by the careful selection of materials for the concrete and cement with which the vaulting is primarily constructed.
The dome's deep coffers were originally plastered and possibly gilded. A large circular opening (oculus) at the top of the dome admitted light.
