Background: 

When the ancient Romans built their temples, they often built a tall staircase to the front to protect the building from frequent floods of the Tiber River.  The pantheon is no exception.  It is hard to believe today when seeing the Pantheon that at one time there were 15 steps leading to the front door.  Now, over the centuries, dust and debris has covered those step and raised the front to the level of the street.

What tourists see as they relax in front in the Piazza della Rotonda is drastically different than that original temple. Hadrian rebuilt the structure; maker's stamps in the bricks proving restoration to have been between 118 and 125 AD. Still, the inscription on the architrave attributes the construction to Agrippa during his third councilship.  Some historians believe that Hadrian incorporated this inscription to reinforce his links to Rome's ancient imperial line.  The portico in front of the Pantheon is what remains of Agrippa's original temple.

It still holds the record for the largest unreinforced concrete dome in the world.  It is mathematically perfect: you can inscribe a perfect globe inside it, Michaelangelo said it was designed by the angels.

It was the first temple dedicated to all the gods - Pan = all, theon = gods.  Previously the general public could not enter temples, they were the reserve of priests and Vestal Virgins.

In 609, Emperor Phocas gave it to Pope Boniface IV who consecrated it and dedicated it to St Mary and all the martyrs.

It has been the victim of spoilation over the centuries, notably Pope Urban VIII, the Barberini Pope, "recycled" bronze from the Pantheon to make the canopy over the high altar above St Peter's tomb in the Basilica and canons for Castel Sant'Angelo.  This led to the saying "What the barbarians did not do to Rome, the Barberini did."

Location and Directions:

The Pantheon can be found on Piazza della Rotonda and there are several means for arriving at this attraction.  By underground, the nearest stop is Barberini (linea A) - 450 metres from Pantheon. By bus, you could take n° 30, 40, 62, 64, 81, 87 e 492: their stop is in Largo di Torre Argentina, 400 metres from the Pantheon.