There is good news for lovers of Art Nouveau, one of Europe's oddest cultural phenomena. Walk down Andrassy Street in Budapest, and you will find elaborate and bizarre examples of this strangest of architectural adventures, now restored to their former extravagant glory.

Thirty years ago, when I first visited the Hungarian capital, its Art Nouveau buildings were blackened by pollution and crumbling from neglect. The ruling Communist regime had been too broke to replace them with the concrete boxes then blotting post-war Europe, a blessing in disguise.

During the grim and dispiriting era before the fall of the Berlin Wall in 1989, my husband and I travelled throughout Hungary on several occasions, finding long forgotten Art Nouveau and Eclectic treasures. We met brave locals who risked their liberty to catalogue and preserve buildings with very limited resources. It was a political statement to save such symbols of "bourgeois decadence," not least because Art Nouveau had been an expression of Hungarian nationalism, something the "comrades" were loath to recognise or encourage.

Hungary's version of Art Nouveau drew on medieval motifs and symbols, central to their identity before they were subsumed by the Austrian Empire. Hungary eventually threw off the Hapsburg yoke: the Communists did not wish the citizens to repeat the process, jettisoning the Soviet empire.

Hence there was official disapproval of Art Nouveau because of its frivolity, but there was also an anti-Semitic sub-text: many of the architects had been Jewish, as had their affluent clients. Being outside the stifling Victorian-era establishment, some successful Jewish entrepreneurs were prepared to support daring, new artistic ideas, among them Art Nouveau design.

Thirty years ago it was humbling to be with people who had put themselves in danger's way to defender their artistic heritage. It was equally exhilarating to find sublime examples of Art Nouveau, mostly unknown to the rest of the world. But as we surveyed the fading peacock mosaics, the disintegrating wrought iron dragonflies, the chipped majolica flower tiles and the crumbling stucco decorations crawling across buildings like vines, we wondering how long these unusual creations would hang on. Yet, against all the odds, they outlasted their Communist detractors.

Now, along Budapest's loveliest avenues, luxury brand retailers more familiar on Fifth Avenue have come to the rescue. They have renovated battered facades and modernised interiors, restoring once fashionable districts. In addition, hotel chains have spent millions resuscitating flamboyant, glittering Eclectic interiors, such as the New York Palace Café.

Thirty years ago we wandered through the dark, garbage-strewn arcade of the long abandoned Gresham Insurance Building, at the Pest end of the Chain Bridge. Perhaps the finest Art Nouveau building in Hungary (and one of the world's very best), it had been left to die. Thanks to the Four Seasons group, the Gresham Palace now sparkles once more, part Hindu temple, part luminous Klimt painting.

All over Budapest lovely old wrecks have been restored. Turn a corner and you are confronted by a mosaic of a longhaired beauty in flowing robes, an orgasmic swoon on her Sarah Bernhardt-features, Nouveau tendrils swirling around her, as if in zero gravity.

The Book Café in the former Paris Department Store is back to its jewel box self. The interior of the Museum of Decorative Arts, by the local genius, Odon Lechner, is once more a dazzling vision in white, as if a Maharaja's palace had been transplanted to the Danube. The central synagogue, from the same era, is a sublime Andalucian vision once more, and, at the zoo, there are handsome Nouveau baboons, polar bears and elephants stoically guarding renovated Islamic-style crocodile houses.

Alas, some masterpieces, like the Parisz arcade (recently featured in the opening scene of "Tinker, Tailor..."), are without a corporate saviour. In Pest, street upon street of handsome yet dilapidated buildings still bear the shell and bullet marks of the ill-fated 1956 Hungarian uprising against the Communists. It will take a stronger economy to nip and tuck every worthy candidate, but the burghers of Budapest clearly know they have a unique stock of tourist-worthy treasures.

Some of Hungary's finest Art Nouveau inheritance was cruelly abandoned in what is now Romania. As punishment for being on the wrong side in World War One, two thirds of Hungary was awarded to its neighbors. Timisoara and Oradea were thriving Hungarian cities until 1914. Now they languish in western Romania. Almost every street has world-class Art Nouveau gems. Yet both towns are too poor to attract fairy godmother luxury goods emporia.

In Oradea, city officials have embraced their architectural heritage, celebrating the ubiquitous presence of Art Nouveau. Among the dozens of jaw-dropping buildings, many have been beautifully restored. The atmosphere is hopeful, despite the stumbling economy. It is a delight to wander the city's squares and streets, and sit at its pavement cafes.

By contrast, Timisoara, three hours to the south, looks as if a brutal, street-by-street conflict has just ended. Once a cosmopolitan Austro-Hungarian city of wedding cake stucco facades and fine squares, parts of Timisoara teeter on the edge of destitution. Armed with a few notes from a long-dead Hungarian architect, we negotiated shattered, Baghdad-style streets and sidewalks jutting at post-earthquake angles. Sewer covers had long since been stolen, and packs of wild dogs patrolled their manors.

Like Oradea, Timisoara has dozens of Art Nouveau gems, including a bizarre yet deserted, fortress-like abattoir, an elegant battery factory, now a scary-looking nightclub; a hydroelectric plant, also once the cutting edge of architecture. None seem to have been touched in a century.

It isn't only architectural heritage that is neglected in Timisoara. According to some who risked their lives to overthrow the Communist dictator Ceausescu in 1989, the city's noble role has been sidelined. It was in Timisoara that civilians courageously took to the streets, repeatedly calling on Ceausescu to go. Soldiers and police killed more than a hundred before the uprising spread to other cities. What began in Timisoara culminated in the execution of a tyrant, but, "the Communists just re-branded as democrats and they're still in charge," explained one former protestor, still limping from the bullets he took in 1989.

Old women in faded polyester dresses shuffle along pot-holed streets, their frail bodies knarled from decades of Ceausescu's regime. SUVs cruise past, driven by the offspring of former Communist Party officials who bought the very state assets they privatised at bargain prices. Wealth exists, but the bling-bedecked gangsters who have it don't appear to care about culture, history or the elderly.

Romania's Art Nouveau, like its older generation, deserves a medal for surviving Ceausescu. It would be an art crime if the age of freedom saw the demise of an architecture style more popular than ever.