A rundown of the main streets, piazzas, and neighborhoods to help you navigate the Eternal City
Rome is strung along an S-shaped bend of the Tevere (Tiber River). The bulk of the centro storico (historic center) lies east of the Tevere. The Vatican and Trastevere lie on the west banks of the Tiber.
For the purposes of major roads and arteries, know this: for all intents and purposes the geographic center of Rome is Piazza Venezia; everything radiates out from this point. Dividing the city into neighborhoods is a bit trickier.
The classic neighborhoods of Rome
There are many ways to slice the map of Rome into smaller, bite-sized neighborhoods: the famous Seven Hills of antiquity, the medieval rioni neighborhood designations that are still used officially but mean little to non-Romans. (Sure, you might have heard of the popular rione called "Trastevere," but what about rione "Borgo?" Unlikely; but if I said "The area around the Vatican" you'd instantly know where the Borgo was.)
However, most official divisions are fairly useless to the traveler. Most tourists simply want to know which area of town is which, where the big sights are, and where they would they be happiest finding a hotel.
The ReidsItaly.com neighborhoods of Rome
A quarter-century of living on-and-off in Rome has taught me that, regardless of historic or official demarcation lines—or even of major streets of squares—once you're on the ground and walking around, the Rome a visitor sees naturally falls into about 11 neighborhoods (well, 10 neighborhoods plus one for everything "beyond the walls").
Those are the ones I will use. I'll label some descriptively, some using the rione name, and some using the good ol' Seven Hills, but each will be anchored by two or three major sights or landmarks so you'll know where I'm talking about.
We'll start with the three neighborhoods at the very heart of the historic center, the area 90% of tourists want to spend most of their time in: The Tridente, Upper Tiber Bend, and Lower Tiber Bend.
Piazza del Popolo, the Spanish Steps, and the Trevi Fountain: Shops, restaurants, and sights
The areas around Piazza Navona and Campo de' Fiori are crammed with sights, hotels, and restaurants
The boho medieval neighborhood across the Tiber around Santa Maria in Trastevere and the Gianicolo
A leafy residential hill above a restaurant-filled working-class neighborhood
Personally, I am partial to the Streetwise TK map—amazingly detailed yet tiny, a foldable and laminated map that slips into your (deeper) pocket.