As a history buff... The Coliseum, Vatican City, Sistine Chapel, all the various churches in Rome. We went to Pompeii (great) and hiked up to Vesuvius (dead volcano my ass). Great place to go.
The only time we ran into what might have been an issue was on a train, some "gypsies" were walking down the aisle making a lot of commotion, and our 2 friends (both cops) said to watch your
wallets, the commotion is a distraction. Parking is difficult, and one guide told us that traffic laws (such as double parking) were more of a suggestion. Be prepared to see heavily armed police
and soldiers all over. Don't drink the tourist wine, find a local wine store and get what seems to be popular.
Last suggestion: When eating out do NOT order Bud, Coors, etc, they are IMPORTS and cost more than your meal !!!!
Have a wonderful time.
