The dark past always hovers in Berlin. It haunts the cabaret on stage, performs in digitised old film reels and can arrest you on the street. On Kurfurstenstrasse, a main road in Schoneberg in the city's inner west, a bus stop poster harks to the Holocaust, declaring in bold English, "Never forget."
As Berliners search for the core of their reunified sprawl there is little risk of collective amnesia about the aesthetic loss, at least.
Bombed extensively during World War II the city's architecture is a pick and mix of surviving neo-classical buildings sandwiched between post-war knock-ups. The tensions of the city have produced exciting art and nightlife but the exterior trimmings are often utilitarian and cold.
Seventeen years after the Wall separating east from west came down Berlin seems destined to remain more gritty than pretty. There is a glut of cheap housing but unemployment is about 17 per cent. One wonders how past traumas inflicted variously by Hitler and then the German Democratic Republic and its feared Stasi (secret police) must play out in everyday human transactions even today, as Western freedoms cross-pollinate with those still clinging to old authoritarian ways.
At first, upon our early evening arrival, the three-star, six-floor Schoneberg hotel seems reasonably efficient. "Art nouveau" and "lovely", with "French-style beds", the websites had said, and the hotel exterior is faintly decorative. The sixty-something woman with the dyed black hair at reception explains after accepting our credit card that water leaks through the ceiling have forced her to move us into a standby room, but she appears not to hear my query about whether our ¿94 ($154)-a-night tariff will be discounted. The rate is inexpensive by major city standards, so we shuffle upstairs.
But our Berlin bargain on the second floor contains two single basic beds pushed together. These are each fitted with one sheet, with a quilt rolled up at each base. There are two whisper-thin lumpy pillows. A rickety plywood cupboard contains one hanger and has a portable TV perched up top. The wallpapered walls are scuffed.
In the bathroom, there are no towels or toiletries. Cold running water but not hot. The room seems to be a staff member's accommodation hastily vacated. Deflated, I unroll one quilt after the woman leaves the room and lie down for a moment's repose. The mattress bows in the middle.
My other half takes the lift down to reception and requests another room. The woman suggests we could change rooms in the morning, so he delivers the ultimatum: a new room now, or we leave the hotel immediately. "I'll move some people out of another room," the woman replies. No, we don't want to evict other guests. "This is not a problem, they are regulars." Eventually we are shown another, empty room on the fourth floor, with a slightly water-damaged ceiling. This room is marginally more comfortable than the last one. We have stumbled into Germany's answer to Fawlty Towers.
Strangely, a stiff drink or two and some raucous entertainment seems in order. So we head to a nightclub called the Kleine Nachtrevue.
In the years before the National Socialists' rise to power in the 1930s there was a more libertine attitude, which was acted out in the cabaret on the Berlin stages. In the 21st century vestiges of that old decadence can still be found. We wander along Kurfurstenstrasse and press the buzzer at number 116.
A couple of minutes later the door is opened by a tall, good-looking bespectacled and smartly dressed woman with high cheekbones and blonde hair tied back. She would not look out of place in a law firm. Inside is all green and gold: green seats, gold tablecloths. Mirrors back the full-length drinks bar and a large candelabra burns away. We pay our hostess ¿25 and take our seats at the back with about 35 other people. Our gin and tonics are brought to our table, with a blue and a yellow naked woman swizzle stick in each.
The lights are dimmed and from behind the curtains a woman emerges who looks suspiciously like our hostess, her blonde hair let down, spectacles discarded, the pants suit replaced by a body stocking through which one can spy her breasts, atop a purple latex fishnet frock. She is singing Marlene Dietrich's Falling in Love Again in German and a dark-haired woman joins her on stage.
Safe territory? Not quite. Behind the women on stage is a menagerie of "toys": handcuffs, a paddle, a cat o'nine tails, a wooden spoon, a saddle. The pair are accompanied by a manic pianist, a chap with long, unwashed hair who sounds a little like Tom Waits might sing in German. He will later be slamming the tables at the front with his fist and screaming at everyone as part of a jolly night's entertainment.
An audience member by the name of Thomas is tied to a chair and serenaded with an ode to Thomas in German. His friends laugh at his humiliation. The trio cleverly put the S&M implements to use as musical instruments on each other: chain clinking, paddles slapping, whip cracking. It looks like good, naughty fun, until we see the dark-haired woman pass us by obviously affected by her ordeal.
There is a musical number that involves the dark-haired woman wrapping the pianist and the blonde in cling wrap. The blonde then begins singing in English, "rape me". Is this some allusion to Britain's emasculation of Germany, or just avant-garde theatre being whacked out for the sake of it? Marlene was never this nasty, surely?
Outside, in one of Berlin's most gay areas, Schoneberg boasts a preponderance of fetish shops. Military uniform and leather alteration retailers seem as common as convenience stores. Post-Wall freedom seems to have simply renewed a kink for discipline and confinement.
Kitsch souvenir stalls are to be found where Checkpoint Charlie once stood. Designer stores such as Gucci and Vuitton mark Friedrichstrasse in Mitte in the old inner-east. To avoid the tacky tourism we head down Zimmerstrasse, taking in Mitte's interesting and undervisited art galleries.
The works here grapple with the artists' place in the world. The building at 90-91 Zimmerstrasse is home to several galleries, including the premises of Max Hetzler, who was first to move his gallery into the neighbourhood in 1996. The building was once a propaganda-publishing house. In one gallery, a staff member tells me the basement was used as a prison by the Nazis during the war.
A little to the west, Potsdamer Platz - Berlin's attempt at a new commercial heart - has bland food and Hollywood movies for the tourists. But it's the new Berlin Film Museum inside the Sony Centre that is the big surprise. This cine-
labyrinth of mirrors, movies and sound pays homage to Fritz Lang's 1927 classic Metropolis, deconstructs Leni Riefenstahl's controversial oeuvre celebrating the Aryan human form and charts key moments such as the 1936 Berlin Olympics.
It critiques the National Socialists' co-option of German cinema for anti-Semitic and war-mongering propaganda, courtesy of Goebbels's 1933 appointment as Reich Minister for Public Enlightenment and Propaganda. That particular room looks, perhaps deliberately, like a mortuary, with walls of steel drawers containing one propaganda film nasty after another.
And, of course, there's Dietrich. A room displays her costumes, including one of her gender-bending top hat and tails outfits.
More curious is the 1929 audition tape, on a continuous loop, on which Germany's greatest actress sings sweetly in English about her man being the cream in her coffee. The next moment, in a Jekyll and Hyde snap, she mock-slaps her pianist on the back and shouts abuse at him in German. Marlene, it seems, could play out her dark side for an audience too.