[Rome] Pantheon
In the aftermath of the Battle of Actium (31 BC), Marcus Agrippa started an impressive building program. The Pantheon was a part of the complex created by him on his own property in the Campus Martius in 29–19 BC, which included three buildings aligned from south to north: the Baths of Agrippa, the Basilica of Neptune, and the Pantheon.
The 4,535-tonne (4,463-long-ton; 4,999-short-ton) weight of the Roman concrete dome is concentrated on a ring of voussoirs 9.1 metres (30 ft) in diameter that form the oculus