The Pantheon was originally a temple built under Hadrian to worship all Gods, hence the name. It has a very long use-history, being in constant service up to now. From the 7th century onwards it was used as a church. Two kings and quite a number of artists and architects found there resting place in this church.
In the 7th century the bronze ceiling and everything metal was torn down and melted down. Here is a look up the dome towards the oculus, compression ring and lighting source combined. At first I thought this was a modern interpretaion in concrete. But it is actually Roman concrete. I really didn't like it too much because of this modern concrety style. Concrete is not my favourite building material.
Next was the Vittorio Emanuele II monument, with the 'altar of the fatherland'. Victor Emanuel was the 19th century king who unified Italy. It is built of white marble and very visible since it sits, gleaming white, on a hill. The equestrian statue in front of the building represents King Vittoria Emanuele II. And the two four-in-hands are lead by the goddess Victoria.
Here are some details:
And a view from the top of the stairs down to an excavation, what a nice view for an archaeologist :)
The Area Sacra di Largo Argentina is the oldest temple complex in the city. It was built in the 3rd century BC and discovered under Mussolini and, alas, excavated in the late 1920s. A lot of information has been lost during these not very sophisticated digs. Here you can see one of the remaining four temples:
Strangely enough, it is also famous for its cats. No sooner was it excavated than it became a 'cat sanctuary' for stray cats.