For an unique history lesson, visit the crumbling remnants of Forum of Vespasian and imagine how it looked in its prime.
You'll have sightseeing choices galore when spending time in Rome City Centre. Forum of Vespasian is a good place to kick off here, but there are lots of other fine spots to appreciate. St. Peter's Basilica, Roman Forum, and Piazza Navona are close to the once-important structure and will round out your day nicely.