239. Pantheon, Rome, c. 118-128 CE (Italy)

The Pantheon, one of the most impressive and well-preserved of all Roman temples, can well claim to be the most influential building in the Western tradition. Erected in the reign of the Emperor Hadrian (who is sometimes given credit for its architectural design), the Pantheon was a place for worship of the seven planetary deities. Its hemispherical dome, covering a round-plan cella, was the largest in the ancient world. The dome’s recessed coffering is both decorative and functional, as it serves to reduce the total weight. An open oculus at the top allows light and air to penetrate. The temple’s thick walls contain a series of arches and vaults for extra strength, as can be seen on the exterior. Recent research has discovered the original tracing ground for the Pantheon’s building elements, which suggests that the portico is not as tall as was originally intended; this is due to the fact that the columns were quarried out of single pieces of stone. This also explains the awkward presence of a second, taller pediment partly obscured by the main portico. Later imitations of the Pantheon are numerous, and any domed building in the Classical style inevitably owes something to it.