Argentines tell a wry joke about themselves that goes a long way toward explaining why they are so unpopular with their fellow Latin Americans.

"How can you make a fortune overnight?" the riddle goes."Buy an Argentine in the evening for what he is worth, and sell him the next morning for what he thinks he is worth," is the barbed reply.

Argentines' pride in themselves and their country - which can easily spill over into boastfulness and arrogance - reaches its apogee in Buenos Aires, without doubt the most sophisticated and cosmopolitan capital in the southern hemisphere. Nor is the city ashamed to flaunt itself deliberately: When the Avenida 9 de Julio was built, its planners carefully made it just a whisker wider than Paris's Champs-Elysees to ensure its place in the record books as the broadest thoroughfare in the world.

That sort of consciously grand gesture is typical of Buenos Aires. Typical, because it was made in the early years of this century, when the city was at the peak of its international fame, reveling in the glory of fabulous fortunes made from the prolific panpas, the treeless plains of the interior. And typical because today it casts into even greater relief the sad state of Argentina after half a century of economic decline.

Nostalgia is strong for the glorious days before the Second World War, the days when Buenos Aires was the busiest port in South America, shipping beef and wheat around the globe; the days when Argentina was the eighth richest country in the world. It had more telephones per citizen than France and more automobiles than Japan. And nostalgia drips from every mournful, stretching chord of the music redolent of unfulfilled promise that gives Buenos Aires its soul: the tango.

Tango is not so much a dance as an attitude toward life in Argentina, a mood that pervades the city even when you are out of earshot of the music itself. And that is not easy. Take a taxi and chances are that the driver will be tuned into FM Tango, which plays nothing but, 24 hours a day. Walk down Calle Florida after dark and at least one old man will be bent over his accordion, squeezing out a lament about a long-lost love, a cap at his feet.

Around him stands the beauty that Buenos Aires's wealth bought once upon a time, preserved in facades designed by the best European architects of the day who allowed their imaginations free reign. Money was no object. Though many of the city's finest buildings have been destroyed in the past quarter century of philistinism, the streets of several wealthier quarters are still a riot of art deco, art nouveau, mock Gothic, and imposing Parisian.

Some families have retained their wealth. But many, like their country, have fallen on harder times. And the tide of European antique treasures that once flowed into Argentina is now on its way out, as American and English auction houses send their buyers here.

In the rundown barrio of San Telmo, on Calle Defensa (south of Casa Rosada), antique stores offer a glimpse of what the high life once looked like from the inside. On Sunday afternoons I like to stroll around the open air antiques-cum-bric-a-brac market in the Plaza Dorrego, where a little haggling under the shade trees can sometimes net you a bargain, especially in old sliver.

More often than not on a Sunday I am on my bicycle - a mode of transport that would be suicidal on weekdays, when maniac bus drivers rule the streets. On quiet weekends, though, bicycle travel is a welcome escape.

Generally I head for the river, the River Plate that is wide enough here to feel like the sea. Like the pampas behind us, it offers an endless vista of emptiness to relieve any attack of urban claustrophobia.

The ten million inhabitants of Buenos Aires are known as portenos, after the port that first gave their city its life. Today the town turns its back on the port, much of which is dead, but on the river banks to the north and south, portenos indulge in their two primary passions: beef and football.

Beef is central to the Argentine psyche: Their word for a steak is bife (pronounced "BEEF-eh"), and they eat more of it than any other nation anywhere. My Argentine colleagues seek to illustrate the depth of the country's economic crisis to me by pointing out that per-capita beef consumption is only 140 pounds a year now, down from 180 pounds. I have difficulty explaining that this statistic will not persuade my readers abroad that Argentina is on the brink of penury.

In 1913, Buenos Aires's attractions rivaled those of London, Paris, and Rome for the world's wealthy and fashionable. Today they have faded into international insignificance. But it is one of Buenos Aires's enduring charms, when taken with a pinch of salt, that the portenos behave as if they simply haven't noticed.