This is the outside of the Pantheon. The inscription translates to "Marcus Agrippa made it on his third consulship." I have no clue what the hell that means. The outside used to be a lot better looking, a long time ago, but the facade was plundered to make other monuments.
This is a close-up look on the dome at the Pantheon. It's the largest dome in Italy, constructed out of poured concrete. No one seems to know how they got this thing up there centuries ago. It's really impressive, though. There's a 27-foot hole in the middle of the dome that lets the light in that you can see in the picture.