The original Pantheon was a rectangular temple built by Marcus Vipsanius Agrippa, son-in-law of Augustus, the first Roman emperor, as part of a district renewal plan in 27-25 BC. What tourists see as they relax in front in the Piazza della Rotonda is radically different than that original temple.

Hadrian rebuilt the structure; maker’s stamps in the bricks allow us to peg his restoration between 118 and 125 AD. Still, the inscription on the architrave attributes the construction to Agrippa during his third councilship. The portico in front of the Pantheon is what remains of Agrippa’s original temple.