Ran across a young American priest's blog. He's studying in Rome and this is the view from his room.
The more familiar view from the front.
On the site of a temple that Marcus Agrippa had raised in 27 BC, during the Republic, Emperor Hadrian had the Pantheon, shrine to All the Gods, built in 126 AD. In continual use, first as a Roman temple and then as a Catholic church.
And its amazing interior. With the open oculus in the ceiling and the unreinforced solid concrete dome, still the world's largest of that type.