As the fourth course of Sunday lunch arrives, as my girlfriend and I loosen our belts, as we count the calories of our short Roman holiday and conclude that Olympic rowers might struggle to compete, as the Falstaffian host of the excellent La Pace Del Palato brings us our embarrassingly inexpensive bill, as we wonder how "romantic" and "gluttonous" became so confused, as we decide a complimentary pudding won't hurt, I thank the Elysian Fields that Rome is a walking city.

And what a walking city. We arrive for a long weekend late on Friday afternoon. The Boscolo Aleph hotel near the Piazza Barberini (half the rack rate, thank you Travelocity) is spectacular, if a little gaudy. A five-star hideaway based on Dante's Inferno, it is split into floors which are either "heaven" or "hell".

The spa, filled with comely masseuses and sweating businessmen, is heaven. The ground-floor bars, lobby and library are an impressively crimson recreation of hell. The rooms, decked in crisp whites and blues, are heaven. The lifts? I wasn't sure. Maybe they were just lifts. You can only stretch a concept so far.

After a relaxed meal negated any sightseeing on Friday night, we were determined to see as much of Rome as we could on Saturday. Starting early, we make a short trip to the Spanish Steps. It's a good tick in the box, spoilt slightly by the New Romantics selling trinkets and guided tours at the bottom. From the steps, we had decided to make, generally, for the Vatican. It would give us a decent East-West trajectory in the morning that we could then reverse for the afternoon and evening as we returned from the West bank of the Tiber. This plan would, we thought, enable us to see lots of interesting things on the way. And we were right.

What's immediately arresting about Rome is that the two-millenniums-old stuff just lays about all over the place, next to the five-hundred-year-old stuff, next to McDonald's. As a visitor, one can stop and stare at an imperial flagstone or fountain in absolute wonder, while kids on scooters whizz past. The local insouciance to their heaped inheritance is almost as impressive as the architectural wonders themselves.

Just walking around Rome is an endless inquiry, but there were certain things no one should miss. The Colosseum, its flat brickwork ebullient after almost 2,000 years of weather and tourists, is stunning. If you can resist, as we did, the urge to go on a guided tour with a Scandinavian polyglot with a headset, the Colosseum is a place where your imagination can wander. Mine wandered sufficiently to begin quoting entire passages from Ridley Scott's Gladiator. Outside the stadium there were myriad opportunities to pose with statues of my ancestors.

Back in the centre of town, the Pantheon's capacity to inspire awe was unmatched by anything else I saw in Rome, or anywhere. I begun, as everyone must, by admiring the Corinthian columns at the Pantheon's entrance, which are each cut from a single piece of stone and were designed to hide the dome from view. Its second-century architects planned that by obscuring the dome, they would provoke a sense of wonder as people walked in and saw the perfect hemisphere inside. It works. It is all I can do not to fall over when I first look up at the mass of curved stone, punctured only by a nine-metre oculus, a round window through which light streams in.

It takes three scoops of premium Roman ice cream secured from the nearby gelateria to shut me up about the Pantheon. And once we've enjoyed the Trevi Fountain on Saturday night (thrown a coin, resisted the claims of various scoundrels, and been caught in a hail storm), there is nothing to do but have another drink and a nibble.

You may have spotted a pattern. Still, our strict sights/walk/dine regimen seemed to be the only way to do Rome. It is such an urgent, impressive, compact place it requires you to drink it in in one Epicurean flurry. We returned home fat, exhausted and happy. But because there is so much to see and do and eat - because being in Rome is so utterly different to not being in Rome - one long weekend feels like a genuine caesura.