THEY SCYTHED away 14 streets in 1910 to make way for Madrid's Gran Via, a swanky, sassy boulevard built to provide access for the newfangled motor car to parade across town. It remains the throbbing artery of the city, a swaggering highway lined with some of Europe's finest baroque follies, earliest skyscrapers and glitziest jazz-age movie palaces.

In its heyday in the Thirties and Forties, the Gran Via was the height of sophistication, spiked with the whiff of danger that wafted from the seedy neighbourhoods through which it ploughed. Today, if you step from the dazzling main drag, with its endless stream of traffic, you quickly find yourself in quiet allies where drugs and sex are offered and you may be deftly relieved of your wallet.

A raffish spirit persists amid the blinking lights and the churning torrent of people bent on having a good time, piling into cinemas, cafes and fast food restaurants. Clashing with the neon are hand-painted cinema posters looming several stories high, perhaps the last place in the modern world where this engaging, in-your-face art form still survives.

It was a more sombre scene on a chill November morning in 1936 when troops from the International Brigades, poorly armed but disciplined and committed, marched down the avenue to help defend the Spanish republic against Franco's fascists. With their cry of "No Pasaran", these young men from Europe and America helped Madrid resist for three years of civil war.

The Gran Via became known as "howitzer ally" because of the artillery shells that thundered down it from Franco's troops west of the city. They took their sites from the angular Telefonica building, Madrid's first skyscraper, built in 1929 on the highest point of the avenue. This handsome building that still dominates the street was the most bombarded spot in Madrid, and had to be sandbagged, while journalists such as Ernest Hemingway dodged shells and clung to buildings, creeping along the pavements to file their copy at Telefonica, after submitting it first to the Republican censors.

Journalists and militiamen drank and gossiped in Chicote, the bar on the Gran Via that opened in 1931 and never closed throughout all the shortages and terror of war and its aftermath. The art deco curved leather benches and angular mirrors still exert an austere charm, and Chicote's barmen make the best cocktails in town. In the early years of dictatorship, Chicote offered a glamorous bolt hole for celebrities like Frank Sinatra and Ava Gardner, and a focus for black market trading and discreet prostitution.

The Gran Via is no longer fashionable, and critics sneer at the sleaze, the film posters, the fast food joints and tacky shops as kitsch and garish poor taste. But for those who love this roaring thoroughfare, that's all part of the appeal.