Rereading my previous missive made me realise that perhaps I had been rather unfair on my adopted home-town, the town in fact that more than any other I am pleased to consider my home.

Ersatz coffee shops, the litany of local bars being closed down or replaced by peddlers of sportswear, noodle bars and police with riot gear and paddy wagons closing down Brunnenstrasse to evict one of the last occupied buildings in the neighbourhood. Skeptical, to say the least, I may remain as to the revolutionary efficacy of being pissed on beer by 2pm and loitering around U-Bahn stations with stray dogs on string, even if they are called Rosa Luxemburg, Rudi Dutschke or (unlikely given his post-1968 life as a Green MP) Joschka Fischer. But this round of evictions (Auguststrasse 10 is also set to go) marks perhaps the final end of the squatted buildings that flourished in Mitte in the immediate collapse of the Wall. Now you have to go to Rigauer Strasse in Friedrichshain for your anarchist kicks. And nobody wants to go there.

But, still, I was perhaps too hard on Berlin. Things are changing, but for those who take pleasure in seeking out a city's hidden treasures, Berlin remains a treasure-trove. No city in Europe wears its recent history so resplendently on its sleeve, from the DDR show-piece of Alexanderplatz with its Galeria Kaufhof department store (geometric-patterned facade sadly removed), TV tower and world clock, remains the centre of the east-side of a city still peculiarly divided. When I go to the West I do so like a visitor from another town. Some features, of course, are for tourists only, like the Cafe Adler where CIA agents reputedly played draughts and kept an eye on the Stasi officers across Checkpoint Charlie. And then there's the Checkpoint itself, where for a nominal fee a shivering 'guard' will stamp your passpot with an old DDR entry visa. But there is nothing in the guide books about Bernauer Strasse, once bisected by the Wall, and even now an open space so desolate, so redolent of atmospehre, that you don't have to know something bad happened there to know something bad happened there. For psychogeographers, Berlin is as rich with possibilities as the old City of London, with its evocatively-titled street, its alleyways, it hidden churches, parks and firebombed city blocks haemorrhaging secrets from beneath the granite stones and commissioned sculptures of bank office foyers.

Best of all though are those locations hidden from immediate view; the ones for the explorers. And Berlin is rich in them too.

The story goes at Claechens Ballhaus (Auguststrasse) that when its 1990s purchasers were renovating the building and re-opening the downstairs ballroom, with its black-tie waiters, polished wood dancefloor and silver-sparkle decorations, they came across a walled-over doorway. Knocking down the bricks revealed an interior of baroque splendour, covered in dust and flakes of gold leaf, its monumental mirrors cracked from floor-to-ceiling. Rather than renovate, they have left it as they found it, and although it now hosts the occasional evening performance, for the most part it is left untouched. If you can slip past the guard with his pepper and salt moustaches, you will be rewarded with the privilege of drinking with the ghosts of a thousand dinners, dances and theatricals from a century ago, watched from above by cracked cherubs nestling in their golden bowers of ivy, wisteria and lania.

It's one of those venues you arrive at when the night smiles on you. Playing on the grand piano while Shirin sits before a silver candelabra, all 6 candles blazing light on her face and bare arms on the heavy wooden table. Climbing up to the balcony for drunken Romeos and Juliets to declaim their lines for the mirrors and the cobwebs. Finding a bottle of wine hidden behind the bar at precisely the moment when wine was most needed. And all the time you feel that you are contributing to the history of a room with as many secrets as a Catholic confessional, while downstairs in the interest but not stunning ballroom proper couples from their twenties to their seventies take to the dancefloor and waltz the night away courtesy of the in-house band.

Less hidden, maybe, but no less of a treasure is Claerchens Ballhaus' sister venue, Ballhaus Berlin (Chausseestrasse). It harks back to a louche era of men with woolen knotted ties and women with beehives drinking martinis at tables with individual phones. Yes, Ballhaus Berlin has an internal phone system, and each table has its own black bakelite phone on a wooden stand surmounted by a red globe and printed number. Dial the number and you can reach any of the other tables in the room. It is unfortunate, then, that this gem hosts the wonderfully-named but otherwise deeply disappointing Broken Hearts Club, a club night run by Conny, owner of the legendary Rio (now defunct but, word says, due to be re-incarnated soon), main squeeze of Peaches (and titular companion in one of her songs to my very own Shirin), and general local legend. Where better, you might think, to host such a club than a venue where the broken-hearted can confess to each other over telephones mounted at their tables, or don their black duds to slow-dance beneath the globular chandeliers like giant pearls?

So far, so good, but where it all starts to go pear-shaped, as so often in a city that sees itself as both the father and mother of electronica, is the music. Rather than the broken-hearted music you would hope for - Scott Walker, Leonard Cohen, Nick Cave (ex-Berlin resident, no less!), Nina Simone - the DJs instead spin Dead Or Alive, Thriller-era Michael Jackson, or banging techno, while indulging in the interminable but ubiquitous up-and-down head bob that all would-be DJs are compelled to affect when worshipping at their 'wheels of steel'.

Less hidden still, but one of Berlin's most historic venues, is Cafe Moskau. Its 1960s modernist exterior and social-realist mosaics point to its status at the premier venue during the DDR. East Berlin girls in their finest would go there to meet men visiting from the West, snuggling in the semi-darkness on faux-leather banquettes. Who knows what documents exchanged hands there, what illicit records, magazines, books? Now a - guess - electro party venue, Cafe Moskau still reeks of its history, just like the huge apartment buildings, with their glorious belfries, smashed windows and sinister buzzing lights, on the intersection of Frankfurter Tor up the street. To complete a day-night there, you could even pay a visit to the museum for the Ministerium für Staatssicherheit (Stasi), East Germany's feared secret police, by U-Bahnhof Magdalenenstrasse.

Hardly sign-posted, and tucked into a drab building complex now mostly annexed to Deutsche Bahn, the museum itself is actually housed in what used to be the Stasi's central offices. At its height employing over 90,000 people, in addiction to countless informants, the Stasi museum not only exhibits much of the ludicrous yet terrifying array of equipment they employed to keep watch on the nation's citizens - including airtight jars containing rags of cloth which were smeared on suspicious subjects and could be used, with the help of sniffer dogs, to track down wanted individuals (the number of these jars runs into the tens of thousands). The upper floor of the museum, which includes the suite of offices used by the Minister for State Security, Erich Mielke, have been left completely untouched since the Stasi's dissolution in 1989. The 1960s decor and decorative touches including Lenin's death mask remain exactly as they were and, at the end of, you can even have a coffee in the old executive canteen. On my first visit I passed the museum completely, so nondescript was its entrance, which I suppose befits its role in DDR society. But once inside I found it achieved what many museums fail to do: namely, really to bring its subject to life.

This, of course, is merely the tip of the iceberg in a city where the bullet holes of World War II street-fighting can still be seen on the walls of school buildings while the laughter of children playing rises from within. Since the pleasure of exploring is the joy of discovery, I won't give any more away. At least, though, we can say that for all the gingerbread lattes and Vietnamese noodle salads proliferating in the city and creamed over in Ex-Berliner, the English-speaking rag whose job it seems is to create of Berlin the same desert as Time Out in London (in other words, one for the culture vultures), the city is still a treasure-trove for the intrepid.

If you conceive of all cities as living entities, then they all have secrets - guilty or innocent - just as they all have elements of cruelty, kindness, ugliness and beauty. But perhaps Berlin, that experienced more upheavals in the last 50 years than any other Western European city, has more secrets than others. And as much as connoisseurs of loss have plenty to lament in the changes that are taking place here on a daily basis, those treasure-hunters for the secretive, the underground and the esoteric can spend no better time than by drifting through streets that still whisper of their past, where ghosts still walk, and dust-gathered beauties are still only on the other side of the door not yet opened.