Italy's cuisine can change with every bend in the road. Each town, each valley even, seems to have its own distinctive culinary treat. And Modena, an ancient city in the rich plain of Emilia-Romagna province, is no exception.

On a recent two-week tour of central and northern Italy, tagging along with a group of food writers, I found myself headed toward this city I'd never heard of, questing after its specialty -- balsamic vinegar. What I discovered was not only the vinegar, a rich aromatic elixir that has become a cult ingredient in America, but a beautiful city blessedly free of the crowds that seem to choke other, better-known Italian towns.

Modena is a city to wander, savoring its colors and fine proportions and openness. The city center -- an area of about one square kilometer, easy to stroll around in an afternoon -- is interspersed with attractive plazas, all connected by a web of narrow streets anchored to a central cathedral square. The architecture, except for the Romanesque cathedral (one of Italy's most famous), is mostly of a 17th- and 18th-century piece, a harmony of graceful four- and five-story fac,ades, often with arcades at ground level and topped with tiled roofs.

Modena is also a city to see from a sidewalk cafe', lingering over coffee. In America it would be known, in urban planner parlance, as a "liveable city."

Modern Modena is synonymous with the names Maserati, Ferrari and Fini -- names that mean fast cars and fine food. On the city's eastern outskirts are the automotive factories and food processing plants that bring today's prosperity.

But in the old city, once surrounded by high walls and now circled by a green sward of public park, you'll find the legacy of other names -- the family of Este, the architects Lanfranco and Avanzini and the 12th-century Lombard sculptor with the quaint name Wiligelmo. These men and their families created Modena's cathedral, its palaces and, in the case of the Estes, the financial and political base for Modena to thrive as a city.

The Este family, who ruled the city most of the time between 1300 and 1800, amassed one of the finest art collections in Italy. And it's worth a trip to the 18th-century Palazzo dei Musei to see it. Although the collection was diminished, first by Duke Francesco III -- who sold part of it to the King of Poland to pay municipal debts -- and later by Napoleon -- who shipped some 20 paintings back to Paris -- there is plenty left: works by Veronese, Tintoretto and El Greco, Tuscan primitives and examples from the Flemish and German schools. The Este Gallery, as the collection is called, is open from 9 a.m. to 2 p.m. (1 p.m. on Sundays), and closed Mondays.

Also in the Palazzo dei Musei is the Este Library, one of the most valuable in Italy, with 600,000 volumes and 15,000 manuscripts. Borso d'Este began the basis for his family's collection in the 15th century. His own Bible, its 1,200 fragile pages encrusted with flowers, scenes of prophets and angels, scrollwork, all the intricacy and color we associate with Italianate illumination, is on display, 10 a.m. to 1 p.m. daily except Sundays.

The Este family left another treasure to the Modenese -- the Ducal Palace itself. Built in the Baroque style of the 17th century by the architect Avanzini, it now houses the Infantry and Cavalry Schools -- the Italian equivalent of West Point. The adjoining ducal parks have been converted to a public garden, part of the ring of green that almost completely surrounds the center of Modena.

But Modena's high point -- literally, since it includes a 67-meter tower -- is the Cathedral of San Geminiano. Dedicated to the city's 4th-century patron saint Geminian, it was designed by the Lombard architect Lanfranco and begun in 1099 by the Modenese.

It is not a massive building, and the Ghirlandina, as its tower is known because of its garlanded weather vane, reminds one of the building's modest height. As so much else in Modena, the cathedral has a human scale, as if its decoration (principally the wonderful and often whimsical carvings by Wiligelmo) were put there not just for God to see but for man to appreciate. Plan to spend plenty of time examining the stonework around the cathedral doors, which tells the stories from Genesis.

Also plan to sample the cuisine of Modena, the mainstays of which are delicate filled pastas, air-dried ham or prosciutto, and a variety of salamis, the most distinctive of which is zampone or stuffed pig's trotter. The latter hang in every butcher-shop window, looking not so much like pigs' feet as fat little pigs themselves.

Before the zampone are stuffed, all bone and cartilege are removed, leaving only the skin of the shank and four little toes. When the zampone is filled with an aromatic sausage mixture, the two middle plumped-out toes look like ears. The Modenese boil the zampone, along with other cured meats and salamis, and serve them with a variety of relishes flavored with their treasured balsamic vinegar, the ingredient that drew the food writers to Modena in the first place.

It is remarkable that balsamic vinegar, which has become something of a rage with American food aficionados, is virtually unknown elsewhere in Italy. In this country, cooks pay about $8 per eight-ounce bottle for it in specialty food shops. In Modena, it's homemade in the attic, or made in larger quantities by the food company Fini, which exports virtually all its vinegar to Williams Sonoma in California.

Balsamic vinegar is not a vinegar in the true sense, since it is not just a further fermentation of, say, a red wine or cider. Making balsamic vinegar requires a slow boiling of trebbiano grape juice and then a slow aging over about six months of that concentrated juice in huge 800- to 900-gallon wooden barrels. Next the mixture is transferred into somewhat smaller barrels.

As the vinegar ages, and evaporates, it is transferred annually into succeedingly smaller barrels, until -- after five or more years -- it is ready to be bottled. All the barrels -- from the initial 900-gallon to the final two- to three-gallon ones -- are built of juniper, chestnut or ash, and, most importantly, they have acquired over the years in their grain the yeast or "mother" that produces the vinegar.

According to Giorgio Fini, president of Fini, during a tour of the Fini balsamic vinegar-making operation, old barrels are never thrown away. New barrels are simply built around the disintegrating old ones, so that the "mother" is never lost.

We were fortunate enough to visit not only the Fini operation but a smaller one run by Giuseppi Cattani, a Modenese man who, when he inherited his grandmother's vinegar casks, started making vinegar as a hobby. He now has a small business on the outskirts of the city, supplying specialty shops and individual buyers.

The care and attention lavished by the Finis and Cattani on their vinegar yields a coffee-colored liquid with a complex sweet-sour taste, rather like an unsweet liqueur. It has over the years been considered a tonic for just about anything, and opera singers are said to gargle with it. A bit poured over fresh strawberries makes a piquant dessert, and a few ounces used to deglaze a pan after saute'ing any kind of meat will create a tasty sauce.

Modenese families take pride in their vinegar. Whole dowries used to be paid in casks of it, and it is said that as the city was being evacuated in World War II, some fleeing Modenese strapped barrels of vinegar onto their bicycles. It is an ancient ingredient, having been made in the city for nearly 1,000 years, always in the same way.

That is true even in the otherwise ultramodern Fini plant. While the balsamic vinegar quietly aged and fermented in the factory attic, we saw automated machinery mix, roll and fill pasta on the floors below. Down the hall, electronically programmed ovens and curing rooms automatically cooked and cured about 60 varieties of meats and cold cuts.

The Finis employ about 500 people in their Modenese food concerns, which include the factory, two shops, an excellent restaurant (closed during August) serving regional specialties and an attractive modern hotel, which appears to cater primarily to Italian businessmen rather than tourists. It is comfortable, efficiently run and within walking distance of the cathedral. Rooms run from about $65 a night double (Via Emilia Est, 441, Modena, phone 059-372-717).

And so, if the crowds of Rome and Florence get too oppressive, if you yearn for green parks and wide streets, if you'd like to shop in the chic boutiques without having to fight hordes of other Americans, then Modena is the perfect breather. A gelati eaten in the shadow of the Ghirlandina will refresh you.