On Saturday night I opened a door onto a secret world. A fierce, feral biker-bouncer, pierced and tattooed, stood at the entranceway like a sentinel from Hell. He blocked my path, until I whispered an enchanted password into his knife-slashed ear. The giant stepped aside, letting me, Mrs. Cat and friends enter the eerie edifice. In a concrete chamber troll-like gatekeepers and elfin coat-check girls frisked, stamped and relieved us of our outdoor armour. Then, without a light sabre or magic mushroom for protection, we stepped into the greatest techno club in the world.

Thick smoke filled the sweaty air. Coloured spots swept across the throng of semi-naked bodies. Strobe lights flickered and froze their movement. Strange staircases loomed out of the mist. Above all rose the rhythmic, thunderous sound. The bass beat gripped the chest and pounded the body in waves so powerful that – in the second when they stopped – one felt like a dust mote floating up into the yawning cavern of the building, towards the 18-metre-high ceiling.

In time we would explore Berghain’s surreal labyrinth of hidden bars, disconnected balconies and dark, crowded alcoves. We’d venture up to the packed Panoramabar, with chill-out House music and enormous, trippy photographs by Wolfgang Tillmans. We’d perch on stained sofas, beside butcher’s block tables, around immense, down-lit steel and concrete pillars. But before that we just danced.

In truth Berghain is no secret. The club holds 1,500 dancers. Its scene is both gay and straight, as well as accommodating every intermediate deviation. Around us moved buffed, shirtless boys, slender gleaming girls, a crew-cut dancer with chunky boots and diminutive Hello Kitty backpack, men in lens-less Elvis Costello spectacles, a laughing, bare-chested invalid in a wheelchair. For the most part the dress code was black, minimalist or ‘proletariat’, apart from a dancing queen in white bridal dress and tiara who stood on a plinth above the throng, stirring the smoke with her magic wand. In front of us against the sound system a couple made love without removing – or even unzipping — their clothes. A tall, smiling beauty in a long frock stroked my arm, and turned out not to be a woman at all.

We were at the club to hear Ben Klock, a startlingly attractive and athletic DJ with strong jaw and easy smile (‘crisp and cute’ the smitten Mrs. Cat told me). A long-time resident at Berghain, as well as a producer and label owner, Klock is without a doubt one of the most influential players in contemporary techno. Once a month, in between his appearances at venues around Europe and Asia, he unleashes his hypnotic three-hour sets – with their irresistible beat, moving narrative and signature ecstatic crescendos – at Berlin’s techno central. His show on Saturday night oozed with high spirits, dark sexiness and an irresistible, pulsating beat – giving us our best night out in a decade.

Techno was born in Detroit in the 1980s through the marriage of European synthesizer and African-American music. Funk, Chicago house and electric jazz were combined – and classic tracks reworked — to create a sound that was speedy, futuristic and rebellious. As Ben Klock once told me, ‘I love the shiver that you get from a bass drum. That’s what I love in techno. It demands your attention. It wants to take you on a trip.’ In 1989 at the end of the Cold War, the genre swept through the newly opened gaps in the Berlin Wall. Underground parties took possession of abandoned buildings in the eastern half of the city, flitting from venue to venue, drawing together young people from both sides of the divide. On the dance floors of UFO, SO36 and Tresor, techno became a major force in reestablishing social connections between East and West Germany.

Berghain – near the border between west Berlin’s KreuzBERG and east Berlin’s FriedrichsHAIN – is the reincarnation of Ostgut, a legendary 1990s venue which itself emerged from the male-only fetish Snax scene. In the club there are no mirrors, and no cameras are allowed (hence the frisking), so as to create a safe space where everyone feels comfortable to do as they please. And that is one of the most appealing qualities about Berghain. The club has a raw, grungy, anything-goes physicality, and most straight customers won’t want to explore what happens in the basement (or perhaps to ask why 15 people — 13 men, two women – emerged at the same time from three toilet stalls in the ladies’ loo), yet on the dance floor and at the Panoramabar, the atmosphere feels adventurous but unthreatening — ‘the perfect setting for parties so good that you feel they must be illegal’ according to one commentator. As resident DJ Prosumer remarked, ‘It’s the most intense place I have ever played. The crowd is wild, open-minded, and willing to party. Sometimes, I am so moved spinning there that I get tears in my eyes.’

Berghain occupies an enormous former power plant near to the Ostbahnhof and – with its gifted DJs and energetic dancers – one could be excused for thinking it’s still making electricity. When we left sometime after noon on Sunday, the guest were still arriving in droves, whispering the secret password, passing by the demonic doorman.