The Pantheon was initially built by Agrippa in the first century BC, dedicated to the planetary gods. But the great rotunda was later built by Hadrian (AD 118-128).
The diameter of the dome is greater than that of St. Peter's (42.5 m) and remained unsurpassed till the 20th century.
Model of Rome in the days of
Constantine the Great
Museo della Civilta, Rome
