CONTRARY TO what Starbucks and others of its ilk may believe, it takes a lifetime to perfect the art of espresso-making. No-one knew this better than Ernesto Illy, who died last month aged 82. Illy was evangelical about espresso, which is the essence of Italy. For him, making espresso was a combination of art and science, precision and inspiration, passion and patience. Milk and sugar never passed his lips; nothing was allowed to contaminate the taste of his coffee. Beans passing through the Illy factory in Trieste were subjected to 114 separate checks. "A fine espresso," said Illy, "paints the tongue."

To enjoy coffee at its finest you must go to Trieste and seek out one of its great cafés. On the seafront, its awnings flapping like swans' wings, is the Caffè Tommaseo, which claims to be the oldest in town. It was opened in 1825, when Trieste was part of the Austro-Hungarian empire and a port of significance. The Tommaseo was named after its owner, Tommaseo Marcato, who was also a writer, and it remains a haunt of the literary and the artistic.

Its most celebrated contemporary customer is Claudio Magris, born in Trieste in 1939, one of the most turbulent times in the town's history, and whose name is routinely mentioned whenever the Nobel Prize is about to be awarded. Like Hemingway, Magris prefers to write in cafés, unperturbed by the bustle. You might find him in the Tommaseo, or the San Marco, or the Degli Specchi, situated on the Piazza dell'Unita, sheltering from Bora - the raw, northeast wind that rips in from the Adriatic - or the pigeons which plague anyone with the courage to sit outside.

Each of these cafés is large enough to get lost in, or preserve one's anonymity. "The San Marco is a Noah's Ark," says Magris, "where there's room for everyone - no-one takes precedence, no-one is excluded - for every couple seeking shelter in a downpour, and even for the partnerless."

Just an hour or so away by train from Venice and its madding tourists, Trieste feels like a forgotten place, a frontier town, a crossroads, in which is mixed a louche and potent cocktail of cultures. Five miles to the east lies Slovenia, 10 miles to the south is Croatia. The food and drink served in the cafés reflect the diversity of the population. Officially, Trieste may be Italian but it is really at the epicentre of Mitteleuropa, the kind of town nations haggle over at the end of wars - and then dismiss from their minds. Perhaps that is why it has such a melancholy air. As Jan Morris wrote in Trieste And The Meaning Of Nowhere, it drew to it people like her, exiles of one hue or another: gender-benders, souls adrift, the displaced, the unsettled and the unwanted. "My Trieste," wrote Morris, "has been a place of transience", through which fleeing Nazis might have escaped en route to Argentina or to where Lord Lucan decamped after clobbering his child's nanny to death. "In Trieste," conceded Morris, "anything might be true."

Or not as the case may be. It certainly feels furtive, odd, seductively disquieting. Who is that woman dressed like a gypsy fortune-teller, knocking back grappa and throwing morsels from her plate to a miniature poodle? She could be a once-famous movie star for whom parts have long-since dried up. Or that man in the panama hat reading The Brothers Karamazov, his arm fully extended, as if he were about sing Dostoevesky's words? In Piazza dell'Unita they are building a stage in preparation for a rock concert. An elderly man walks by unsteadily, tapping the flagstones with his copper-tipped cane, as if he were blind. Young boys chase after a football. The wind quickens; waiters shoo scavenging pigeons off their starched tablecloths.

Nearby is the Teatro Comunale Giuseppe Verdi, named in homage to the composer who in the 19th century was infrequently a resident in Trieste. Casanova also spent a couple of years here in the 1770s. Neither, however, is as indelibly connected with Trieste as James Joyce, who came in 1904 and left 15 years later. Here, he wrote Chamber Music, most of Dubliners, A Portrait Of The Artist As A Young Man, his play Exiles, and the first few chapters of Ulysses. Here, too, were born his children, Giorgio and Lucia.

A James Joyce museum was opened six years ago, though its collection is more illuminating about Trieste than it is about its subject. Joyce lived in nine apartments in the town. He taught English at the Berlitz School and frequented a bookshop owned by the Triestine poet Umberto Saba, who became his friend. Joyce was also no stranger to the 250 prostitutes who did good business in what was then a bustling port. Trieste was slow to capitalise on its connection with the famous Irishman. But there is now, among other attractions, a bronze statue of him at the harbour, peering myopically out to sea.

Joyce's favoured café was the Caffè Stella Polare in Via Dante, whose owner, worried that arguments might develop into more violent exchanges, put up a sign saying: "Here we are not talking about politics or high strategy." Sooner or later everyone who visits Trieste must adopt a café as their own. A real café, insists Claudio Magris, is that "with the conservative loyalty and the liberal pluralism of its patrons". The variety of the clientele is what keeps them vital. You never know who might next stumble in, intent on avoiding one of the many thunderstorms in these parts.

Thus the café becomes the setting for a novel and its customers its characters. "Old long-haul captains, students revising for exams and planning amorous manoeuvres, chess players oblivious to what goes on around them, German tourists curious about the small plaques commemorating small and large literary triumphs whose begetters used to frequent these tables, silent newspaper readers " Magris's list is long and Proustian and ghostly.

Another Triestine literary shade is cast by Italo Svevo, the pen-name of Ettore Schmitz, born here in 1861. He is best known for his novel Confessions Of Zeno, in which Zeno, who has an Oedipus complex, struggles with chance, time, marriage and tobacco. Until he met Joyce, who taught him English and encouraged his literary endeavours, Svevo's career as a writer was going nowhere. But the debt was repaid, for many suppose him to be the model for Leopold Bloom who, in Ulysses, wanders Dublin in a blizzard of memories and thoughts.

Joyce and Svevo would often walk around Trieste, discussing everything under the sun, but mainly literature. It is easy to imagine them, the professor and his pupil, promenading along the Riva, on the waterfront, or slowly hiking up the Via della Cathedral to the cathedral of San Giusto, which dates back to the fifth century and from which there are wonderful views across the Adriatic and over Trieste. Then the pair go downhill, all roads leading to one or other of their chosen cafés, there to sip a jolting, creamy espresso, doubtless served by one of the forebears of Il Signor Illy's coffee empire.

MORE INFORMATION The Savoia Excelsior (Riva Del Mandracchi 4; www.starhotels.com) has rooms from £76 and the Hotel James Joyce (Via die Cavazzeni 7; www.hoteljamesjoyce.com) has rooms from £84.

Caffè Tommaseo is at Piazza Tommaseo 4/c (www.caffetommaseo.com); Caffè San Marco is at Via Battisti 18; Caffè Stella Polare is at Via Dante 14. The James Joyce Museum is located in the Attilio Hortis Public Library, Piazza Hortis 4.

GETTING THERE There are no direct flights from Scotland to Trieste. Alitalia (www.alitalia.com) flies daily from London Heathrow to Trieste from around £130 return; and Ryanair (www.ryanair.com) flies from Stansted from around £40 return. For flights to Heathrow, check www.ba.com. For flights to Stansted, check www.ryanair.com.

CARBON FOOTPRINT Approximately 0.541 tonnes CO2 on a return flight from Glasgow to Trieste via Heathrow.