It is also a place of manic change, where precarious fashion dictates every facet of human life. You come here to shop, to admire fine works of art and to boogie at some of the best nightclubs in Europe. But the fact is, you can't breathe in Milan. On an everyday level it is insupportable. A heavy cloud of pollution shields the surrounding Alps from view on all but a couple of days a year.
At the same time, Milan feels hard done by. It should be the capital of Italy, not Rome. It is the richest city in Italy, the most hard-working. "I'd just like to know, as a matter of interest, why Rome's zoo remains open while Milan's zoo has been closed?" one astonished resident asked me. The same note of petulance was struck in a locally written guide to Milan that I discovered in my hotel bedroom: "Visitors to other destinations hurry through Milan ... as if a city founded more than 2,000 years ago had nothing more to offer ..."
Well, I wasn't going to hurry through, nor was I afraid of my pores clogging with grime on the quest for monuments and galleries. Let them clog. How could you not respect a place that sets so much store by fine art and high fashion? My stay coincided with the final days of an art exhibition in the Palazzo Reale called L'Anima e il Volto (the soul and the face), depicting how the image of man has changed from Leonardo's heroic figures to Bacon's tortured flesh - something to do with traffic jams, perhaps? The queue for this exhibition coiled round the cathedral square. Not just tourists, but Milanese hungry for culture. In the nearby Piazza della Scala, I found the world-famous opera house similarly booked up months in advance.
At the breakfast table next to me, a businesswoman had laid out her laptop and phone and was logged on before she'd had her first mouthful of cornflakes. But culinary delectation has not been sacrificed to the frenzy of money- making. Call them urban fashion-victims if you like - in Milan, even someone who is vuoto (ie has nothing to do) will give the appearance of being in a hurry - but they still somehow find time to shop at fresh vegetable, fish and meat shops on their way home from work, or enjoy country produce in the city's many friendly, cheap restaurants. As in the rest of Italy, people do not live badly here. Though perhaps they drink more espresso.
I set off through town to catch the sights. Typically, for Milan, the central Piazza del Duomo - despite being pedestrianised - did not offer the welcome break from the roar of traffic that I had hoped for. Instead, when I arrived, I found it blasted by the constant roar of drilling.
Never mind. The vertiginously exhilarating Duomo (cathedral) by itself made my trip to Milan worthwhile. This mountain of marble is the third largest church in the world, after St Peter's in Rome and the cathedral of Seville. Climbing up to the roof - above the statues (3,500 of them in all), pinnacles, buttresses, arches and pillars - I found myself in a silent, almost alpine world. Over a hundred white spires rose up around me, topped by the gold "Madonnina", herself over 100m high.
The vast interior of the Duomo reduces all visitors to the size of ants. I found groups of Japanese inside, moving en masse, preceded by their camcorders like gliding one-eyed robots. Through a pinprick hole, a ray of sun pierced the wall of the cathedral and fell on a gold rod running along the floor - Europe's largest sundial, made in 1786.
Yes, Milan is Europe's paramount city of style - but funny old Catholic traditions still cling to the Duomo. High above the chancel, marked by a red light in the centre of a crucifix, is a crystal shrine containing a nail from Jesus' cross (they say). Every year the archbishop is hoisted up on a contraption painted to look like a cloud. He lifts the cross down, is lowered back down, and parades the relic round the cathedral.
I strolled out of the Duomo and into La Galleria Vittorio Emanuele II, the "salon" of Milan, which is entered through a huge triumphal arch. I saw a glass arcade lined with elegant shops and cafes and tiled with mosaics; from its high domed roof, its designer, Giuseppe Mengoni, fell to his death in 1865, a few days before the opening ceremony.
Next on my sightseeing agenda was the Castello Sforzesco, a red-bricked 15th-century fortress housing several museums. But why should I bother with castles in Milan? There is only one essential thing to do in this city: take the trip round the Quadrilatero d'Oro, or golden square, of designer shops in via Monte Napoleone, via S Andrea, via Spiga and via Borgospresso.
Most of the shoppers these days seem to be Japanese women, whose labelled carrier bags have little bows tied on the handles. But "shop" is not really the right name for such establishments. I would call them temples to style. At the counters, women in fur coats continue their mobile-phone conversations as they sign credit-card slips. In the Gucci shop, I was quoted L575,000 (pounds 250) for a small yellow handbag. Bright yellow, orange and red were the "in" colours for bags on my visit.
But of course that range will have gone completely out of fashion by the time you read this.
ITALY TOP TO TOE
Italiatour (tel: 01883-621900) offers three-night breaks at the three- star New York Hotel and the four-star Galles Hotel in the centre of Milan from pounds 299 and pounds 360 per person respectively, based on two people sharing and including return flights and breakfast.
Go! (tel: 0845 60 54321; net: www.Go-fly.com), British Airways' low-price air operator, flies to Milan from Stansted three or four times a day from pounds 90 return if your stay includes a Saturday night.
Go! (see above) flies three times daily to Rome from Stansted from pounds 90 return, if your stay includes a Saturday night.
John Crossland took the air-conditioned train from Rome to Foggia (tickets cost about L50,000 or pounds 17) which runs every couple of hours and takes about three hours. He picked up a new Punto Corsa air-conditioned car, booked through Italian specialists TransHire, Unit 16, 88 Clapham Park Road, London SW4 7BX (tel: 0171-978 1922).
Hotel facilities in the Gargano generally have some way to go to reach international standards, and in the height of summer it is imperative to check that rooms are air-conditioned. One first-class hotel which is showing the way, with fine cuisine and friendly staff, is the Hotel degli Aranci, Piazza S Maria delle Grazie, 10 Vieste (tel: 0039 0884 708557).
Contact the Italian State Tourist Office, 1 Princes Street, London W1R 8AY (tel: 0171-408 1254; brochures 0891 600280).