But Parma, too, is food: Like other parts of Italy's Emilia-Romagna region, it is famed for its pasta. It is also well-known for its pastries—a legacy, perhaps, of a century of French Bourbon cultural dominance in the city, beginning in the mid-1700s. Most of all, though, Parma is celebrated as the birthplace of two of the world's greatest gastronomic treasures—two wonderful products not only essential to Italian cooking but adopted all over the Western world. These, of course, are prosciutto di Parma and parmigiano-reggiano—ham and cheese as they might be served in heaven itself.

What is Parma's secret? Why is it that this delicately beautiful city, with its yellow and pink buildings, its famously charming citizens, its wealth of art museums and other cultural glories, should be blessed with these two all but indispensible foodstuffs? In a word, it's the atmosphere.

This takes a bit of explaining: Though the word prosciutto simply means "ham" in Italian (prosciutto cotto is cooked ham), it derives from the verb prosciugare, "to dry"—and in common parlance, the term refers to cured, air-dried ham. Hams prepared in this manner are produced all over Europe, from the hearty serrano or mountain hams of Spain to the aromatic jambon de Bayonne from France to the Parma version's main rival in Italy itself, the buttery prosciutto from San Daniele in Friuli. But the rosy-hued prosciutto di Parma, with its silky texture, its earthy sweetness, its vaguely spicy aroma, its faintly salty taste, is widely considered to be the world's best ham, period.

Good cured ham depends above all on three factors for its quality: the pigs from which it is produced, the skills of the artisans who process it, and—perhaps most important—the air that dries it. Prosciutto di Parma is made from two breeds of pig, Landrace and Suino Tipico Italiano, long-legged, with particularly meaty hindquarters and enough fat to ensure a long, slow drying period that won't shrivel them into inedible hardness. These pigs feed only on grain corn and, in an age-old marriage of agricultural convenience, some of the whey left over from the production of parmigiano-reggiano. According to rules established in 1963 by the Consorzio del Prosciutto di Parma, which represents the producers of this special ham, pigs destined to be turned into prosciutto di Parma can be raised in Lombardy, Piedmont, and the Veneto as well as in Emilia-Romagna. Typically, they are slaughtered near where they are raised, at an age of 10 to 12 months and a weight of at least 140 kilos (308 pounds). Wherever the hams come from, they must be cured in the province of Parma, in facilities belonging to members of the consorzio.

This curing is a highly specialized. Ham is made only from the rear haunches. (Culatello, a sort of super-prosciutto di Parma, both more delicate and more expensive, is made not from the entire haunch but only from the posterior muscle or buttocks; it is considered the filet mignon of prosciutto—though it is lower in fat and thus somewhat drier than the regular stuff.) The hams are salted, chilled for about two weeks, resalted, then stored again in refrigerated rooms for about three months longer, while the salt soaks in. Nitrites and other additives are strictly forbidden. When the hams finish this stage of curing, they will have lost about 15 to 17 percent of their original weight of 22 to 33 pounds each.

The hams are then hung to dry for at least 300 days, the legal minimum. To satisfy the demands of the United States Department of Agriculture, those hams destined for the United States are hung for at least 400 days. (This is one case in which American health regulations actually make for a better product, not a compromised one like the imposed pasteurization of imported soft-ripe cheeses. The extra 100 days of age add richness of flavor to the ham—so we might actually be eating better prosciutto here than the Italians.)

It is in this final, long aging that Parma's atmosphere comes in: Without the perfect air currents flowing around the hanging hams at just the right speed, at just the right temperature and degree of humidity, there would be no perfect prosciutto di Parma. Locals love to explain, in terms that are often operatic, how the fresh salty breezes blow in from the Tuscan coast, softening as they waft over the olive and pine trees of the Magra Valley; how their humidity disappears as they cross the Cisa Pass; how those special breezes that decide to linger near Parma take on the perfumed fragrance of the surrounding chestnut groves … It's all quite poetic. And, apparently, more or less true.

Parma itself, on the lower flank of the Po Valley, endures extremes of temperature that would ruin the hams if they were dried within the city limits, freezing them in winter and turning their fat to liquid so that they'd literally leak in summer. Instead, the hams are dried about 15 miles south of Parma, in the rolling countryside around the town of Langhirano. Here, the hams are hung from the ceiling in long rows in multistoried warehouse-like structures with tall, narrow louvered windows. In a modern innovation, these windows are computer controlled to follow the direction of the prevailing winds so that the hams bathe in a steady flow of air. The system works: Experiments have proven that hams hung to dry in similar sheds even a few miles away lack the sweet, unmistakable flavor of prosciutto from Langhirano.

When the hams are ready for sale, Consorzio inspectors make a final check, pricking each one in four places with a porous sliver of horse bone. If a ham doesn't smell right, it is rejected on the spot. Those that pass are branded with a depiction of the Duke of Parma's crown, which guarantees quality and origin. Those that don't make the grade are sold as less-expensive, less-prestigious ham.

Until 1989, information about prosciutto di Parma would have been of academic interest only to most Americans. It had been imported here for decades, but in 1968, following an outbreak of Africa swine fever on the Italian island of Sardinia, the USDA banned all Italian meat products from this country. To stop the spread of the disease—which affects animals but not humans—Italian authorities killed every pig on the island. Not a single incidence of swine fever was ever reported on the Italian mainland, much less in the vicinity of Parma. Despite this fact—and despite the efforts of America's then-ambassador to Italy, the food-loving Maxwell M. Rabb—it took 22 years to get the ban lifted. According to Rabb, it was pressure from American meat-packing plants, not health concerns, that kept the ban for so long. The Italian government found this particularly insulting, since "prosciutto is to the Italians what apple pie is to us." The real story, he confided, is that when the American government wanted to install a cruise missile site in Sicily, they convinced the USDA to revoke the ban on prosciutto as a gesture of good will.

For the best flavor and texture, prosciutto di Parma, like smoked salmon, should be sliced as thinly as possible. If it's thin enough, there's no need to remove the fat. "Fat" may be a dirty word in contemporary America, but it's an important part of the ham. Lean prosciutto exists (and you can always trim the fat away), but its flavor is never complex, and it ends up tasting dry. Connoisseurs of prosciutto in Italy insist that the ham be sliced while they watch; then they eat it within a day or so—at room temperature.

Parmigiano-Reggiano (the name has been an officially registered trademark since 1993)—the real parmesan cheese—is also produced according to strictly regulated methods. Named jointly for Parma and another city in the region, Reggio Emilia, the cheese has the distinctive granular texture common to cheeses of the grana type (named for their fine, small grain)—hard, semi-fat cheeses made in northern Italy from partially skimmed cow's milk. Production of the cheese, by law, may occur only in the provinces of Parma, Reggio Emilia, Modena, and portions of Bologna and Mantua.

Parmigiano (we'll call it that for short, though its producers prefer the full name) is quite possibly the most versatile cheese in the world. In thin slices, it melts gracefully and is never stringy. Freshly grated, it can thicken soups and sauces almost imperceptibly. Shaved into translucent curls, it enhances salads and antipasto platters, and it is positively essential to the preparation of most kinds of risotto and a good many pastas. It is also, of course, grated onto virtually any pasta (except, in Italy, those containing seafood). It is also one of the world's great table cheeses—a cheese to eat in shards and crumblings with a glass of wine—nutty, buttery, and thoroughly delicious. Well-aged parmigiano, four years old or more—the kind that used to be called stravecchio or stravecchione (these terms are seldom used today)—has the color of old ivory and a deep, complex flavor that lingers happily on the palate.

Parmigiano was once made from the milk of a breed of cattle known as vacche rosse, or red Reggiano, cows. Today, these have been almost entirely replaced by Holstein-Friesians, who produce more milk. Traditionally, parmigiano came from milk produced only between April and November, but that distinction was legally abolished in 1984.

The cows are milked twice a day, in the evening and the morning. The evening milk rests overnight in large, open metal boxes, until the fresh morning milk is added the next day. Then a lactic acid starter, made from the previous day's whey, is mixed in, along with pure calf's rennet. Like prosciutto di Parma, the cheese, aged for 18 months, is sampled for quality—in this case, with augers and hammers—and it, too, receives a brand: the words "Parmigiano-Reggiano" stamped on the rind. Parmigiano will age for years in an unbreached wheel—some cheese shops actually sell it by vintage—but once the wheel is cut into, it dries up quickly.

Though many Americans only know "parmesan" cheese as that pale, grainy, rather pungent powder that comes in the green containers (which is to parmigiano-reggiano what a fast-food burger patty is to a dry-aged New York steak) parmigiano-reggiano, like prosciutto di Parma, is becoming an American—not just an Italian—classic. And I think that's something to sing about.