For a fascinating history lesson, check out the crumbling remains of Domus Flavia and imagine how it must have looked in its prime.
You'll soon see why this Rome City Centre once-important structure is visited by many travelers. If you're looking for more to do and see here, St. Peter's Basilica, Roman Forum, and Piazza Navona are in the area too. They won't take you very long to get to from Domus Flavia.