The statue of Marcus Aurelius stands as the centerpiece of the Capitoline Hill. The one outside is a copy of the ancient version, placed in the Plazzo Nuovo off to the side for its protection. The buiding in the back is the Palazzo Senatorio, the city hall of Rome.
Here you see Piazza del Campidoglio, totally designed by Michelangelo, in all it's glory. This view gets itself on the back of Italian coins. The building in the back is the Palazzo dei Conservatori.
Palazzo Nuovo and its collections were built by the popes, and so you get a bust of one of them in the center of the niche in the courtyard. Eventually Pope gave the palazzo to the city as the world's first public museum. In the background above the curved cornice you can see immediately behind the building a small portion of the brick walls of Santa Maria in Aracoeli.
This is a magnificent statue inside Palazzo Nuovo.
These are the parts of a colossal statue of Constantine, the first emperor to embrace Christianity. The statue originally stood in the Forum at the basilica he built. The arm fragment at the left is about as tall as a person.