For a memorable history lesson, check out the crumbling remains of Roman Insula and imagine how it looked in its glory days.
You'll be spoiled for sightseeing choice when in Rome City Centre. Roman Insula is an ideal place to begin here, but there are lots of other worthwhile places to visit. St. Peter's Basilica, Roman Forum, and Piazza Navona are near the once-important structure and will top off your day nicely.