|(Factoid: only 2% of the gladiators survived)|
or the Pantheon.
Notice the fountains--
Try to ignore the throngs of people doing exactly the same thing.
When in Rome . . . fit in as many sites as possible. The centuries and centuries of history leaves one in awe.
When in Rome . . . eat an authentic panini and a pistachio gelato, exhaust yourself thoroughly, and still end it all with a smile.