Building in Rome begun 27 BC, probably as an ordinary rectangular Classical temple, and completely rebuilt by Hadrian (с AD 118–128).
It is remarkable for its size and design; the exact method of construction has never been determined. A circular building of concrete faced with brick, it has a great concrete dome, 142 ft (43 m) in diameter, and a front porch of Corinthian columns with a triangular pediment. The vast space is lit solely by the 27-ft (8-m) oculus at the dome's centre. The interior is lined with coloured marble, and the walls are marked by seven deep recesses screened by pairs of columns.
Pantheon, Rome, begun by Agrippa in 27 BC, completely rebuilt by Hadrian с AD ...
Frederico Arborio Mella