Originally built by Marcus Agrippa in 27 B.C., the temple to the Olympian gods, known as the Pantheon (pan
=god), was destroyed twice before being rebuilt by Hadrian in the Campus Martius
. The Pantheon Hadrian built replaced the one built by Domitian (A.D. 80) that had burned in A.D. 110. The Roman pantheon is now called S. Maria della Rotonda. It still retains the inscription of Agrippa.
The Pantheon has a rectangular forecourt and an interior round cella. Light enters the dome through an oculus (eye) 9 m. in diameter.
Source: Janet DeLaine "Pantheon" The Oxford Classical Dictionary. Simon Hornblower and Anthony Spawforth. © Oxford University Press 1949, 1970, 1996, 2005.