Travel: In search of Sally Bowles

From my window, the deep solemn massive street. Cellar-shops where the lamps burn all day, under the shadow of top-heavy balconied facades, dirty plaster frontages embossed with scroll-work and heraldic devices. The whole district is like this: street leading into street of houses like shabby, monumental safes crammed with the tarnished valuables and second-hand furniture of a bankrupt middle-class."

Thus begins Christopher Isherwood's Goodbye to Berlin. Sixty years since publication, and with all the destruction wrought by pogroms and bombing, by the Wall, by reunification and politically-based building policies, what could be left of the city he inhabited? Toting the volume, together with Isherwood's other Berlin tale, Mr Norris changes Trains, I set out in search. Mr Norris and I arrived in Zoo Station on the night train.

After abandoning his studies in Cambridge, Isherwood moved to Berlin to earn a living tutoring. The two novels to come of this experience (originally conceived as one work and with overlapping characters) form a vibrant day-to-day study of the city in the early Thirties. Isherwood sketches a hilarious picture of the homosexual, prostitute and club scene at a time when, in England, homosexuality was still punishable by law. His characters speak out for premarital sex and gay artists. This open permissiveness is still present in Berlin, a city tolerantly catering for every shade of the sexual spectrum, each with its specialist cafes, bars and clubs.

Herr Issyvoo, the narrator, encounters ordinary people suffering from unemployment, the Crash, the overnight closure of banks and terrible health problems. His landlady, Fraulein Schroeder, has come down in the world. The Nowaks live in absolute squalor. These descriptions contrast strikingly with the well-to-do Jewish families in the west of the city where he teaches unwilling adolescent girls English. He attends Communist meetings, meets leading activists and knows people who are tracked down, tortured and murdered, or who simply disappear without trace. He is, above all, saddened by the wavering political convictions of a large proportion of the population and alarmed by the insouciance of the Jews.

Jews play a prominent role in both stories. Isherwood looks at rich and poor alike, often with a touch of caricature only Jewish writers would dare use today. He analyses the Berliners' ambivalent attitude towards them: a distrust of the community as a whole, a need, even a liking, for the individual, be he the local tailor generous over instalment dates or the money lender. His most powerful portrait is that of the wealthy Landauers, a family of department-store owners, one of whom, numbed by what is happening, nonchalantly throws his daily death threats into the bin, refusing to leave, until one day he is murdered.

Is anything left of Jewish Berlin? For a start, the term is misleading. German Jews had long ago integrated all parts of the city. There were about 172,000 Jews living in Berlin in the Thirties, of whom a quarter were East European refugees. They squatted in the Mitte, dreamed of making it to the New World and eked out a living as artisans. Thus Berlin became a cultural centre for orthodox Judaism. Some are now returning, often to reclaim land. There is a good Jewish bookshop in Joachimstaler Strasse, a couple of cafes and a grocer's store in the Mitte, but they have a touristy feel about them and the food is mostly Judeo-Arab. Next door, the rebuilt synagogue has become a museum.

But replace Isherwood's Jews with present-day Turks and you have a very credible remake of his Berlin. In fact it is the largest Turkish city outside Turkey (125,000 inhabitants), and Kreuzberg is often jokingly referred to as Turkey's 68th state. Turks run the markets, the bakeries, the clothing shops and the fast-food outlets. They have filled the commercial niche that was occupied pre-war by poor Jews. They are generally well accepted in West Berlin and have, as the Jews did, established a lively cultural scene, even if their spread into former East Berlin has created tensions.

As for the setting, Friedrichstrasse is back in the picture, though it has gained in associations. For decades it was a sort of no-man's land, with Checkpoint Charlie astride it and the only underground station linking East and West Berlin beneath it. Slowly, and complicated by land-ownership claims, re-building began. It now boasts a brand-new Galeries Lafayette and many smart shops and is set to be the trendy street it was before the First World War. In Isherwood's time, the fashionable area was already the Kurfurstendam and West Berlin. Zoo Station still serves all destinations west, but Lehrter Station, under construction in the centre of the new Potsdamer Platz, will centralise the capital's railway network. The KDW department store, Berlin's answer to Harrods, outside which Isherwood describes the elderly prostitutes, moved to West Berlin. The site is occupied by the Checkpoint Charlie Museum.

A reversal of circumstances has also occurred in Kreuzburg, the working- class area where Herr Issyvoo lodges with the Nowaks. The Wall made it a backwater shared by Turks and punks on the one side, the post-'68 Alternative scene on the other. Today, with the Wall down and the Oberbaumbrucke across the Spree re-opened, it is fast becoming a central part of Berlin again.

I made for the former eastern sector. Prenzlauer Berg, which escaped a lot of the bombing and is now undergoing a facelift, still contains good examples of top-heavy balconied facades and dirty plaster frontages. I turned off the newly redecorated streets, with their clean pavements, smart restaurants and new Turkish-run Imbiss (snack bar cafes). Minding where I walked and keeping an eye out for crumbling masonry, I found myself in Isherwood's world: the old tenements known as Mietskasernen with their endless dark courtyards, peeling plaster and abandoned bicycles. The Nazis removed decorative elements of "decadent" buildings and the Communists refused to repair them. But much has survived.

Yet even the rebuilding of this energetic and friendly city has resurrected another Isherwood landmark: the Hotel Adlon, on Unter den Linden, is where the lovable Sally Bowles went with her string of outrageous dates.