Quite fascinating to visit and walk on those walls.
It is surely amazing. My favorite sites to visit in Rome are the rebuilt Pantheon and the old Senate House (have to go on the first Saturday of the month) and the ruins of the Forum. Italy is a fabulous place to visit. If you are interested in medieval history Florence is also awesome. I intend to go see Pompeii and Herculaeum next if I can get there with out taking an experimental gene therapy that is not approved by the FDA.