BERLIN - At the far end of the famous Berghain Club, situated a few hundred meters away from the remnants of the wall that once divided the city, there is a hidden side door. It opens only on weekends, for two hours each day. This is the entrance to Lab.Oratory - which is not a center for scientific research, but rather a sex club for men.

It's Friday night, and a number of customers are waiting outside the closed door. As the guard admits them, each is given an opaque black trash bag in which to deposit his belongings. Most also put their clothes inside and remain in just their underwear. Or even just their shoes. The more modest types keep their shorts on. Each person gets a number written on his arm with a black marker. Oh, the associations one has! And then the customers head to the right - and come upon a line of showers .

Inside there are a few hundred gay men, of all ages, sizes and colors, and anything goes. Except for taking pictures or showing up perfumed. The guidelines at the entrance explicitly state: "Dress dirty. No drugs. No perfumes." Drugs are actually a relative matter here.

In one corner, naked men are lying on mattresses, awaiting any call to action. One part of the place is designed like a stone maze, getting increasingly darker as you get further along in it. On Fridays, alcohol is half-price. A drinker's paradise, a pervert's Garden of Eden. Two naked men sit chatting at the bar. Someone comes up behind one of them and does whatever he does. When he's done, someone else comes along. Just like that - casually, and without a condom.

Like practically everywhere else in Berlin, you hear Hebrew spoken here, too. A couple from Tel Aviv are apparently alarmed to hear about the newspaper article I'm writing and beat a hasty retreat, snorting unpleasantly as they go. A 50-year-old Swedish fellow asks "What is that language?" The main dance floor is illuminated with a soft red light, and the music is kept at a decibel level that allows for small talk.

Lab.Oratory is apparently the most famous sex club in this city, and as such is filled with many tourists. The employees are well prepared: They all speak fluent English, not such a common thing in Berlin, certainly not in the sex dens that are supposed to be hidden in the shadows of the city, for those in the know. Maybe that's why when I invited a German friend to join me, he responded that it was "tourist shit" and said he'd rather stay home and watch TV.

Moran (not his real name ), a 30-something Israeli tourist, talks about his visit to Lab.Oratory in revelatory terms.

"It was an encounter in laboratory conditions that brought out inner passions that I'd kept reined in, in regard to sex," he says. "It's a work of art in terms of the design: The music suits the lighting, which suits the scenery, which suits the people. I also find it amazing that no one will touch you without permission or make you feel uncomfortable. I found myself singing with two other guys at the bar, and suddenly all these Germans joined in with us."

But Moran didn't come here to sing, exactly. Shortly after he arrived he says he began talking with an American guy who lives in Cologne. "He was already naked, we smoked a joint, we made out, we spent the night together." This was Moran's first visit to Berlin; he'd been wanting to go for a long time.

"Everybody goes to Berlin," adds Moran. "From my straight friends I heard that it's interesting and pretty, and from my gay friends that there are lots of adventures, fucking going on in all kinds of places, and that it's not Tel Aviv. Israelis have unresolved issues with sex. Here it's natural." He took a two-week break from writing his dissertation - and here he is.

A recurring subject, when conversing with Israeli tourists who are sampling Berlin's hot sex scene, is the difference between Tel Aviv gays and German gays.

"My first night here I already felt 10 times more pursued than I do in Israel," says Moran, smiling. "People here really want to have sex, and they're not ashamed to say so. In Israel, everyone brings all their inhibitions to the table. And Israelis are militaristic and want to control you."

Versatile scene

The Reichstag and the sausage stands aren't the only big attractions here. In the last few years, Berlin's versatile sex scene has become a strong tourist draw. Indeed, there's something for everyone - men, women, gays, straights, S&M aficionados and esoteric fetishes. One can enjoy three museums and two orgies in four days. In The Lonely Planet Guide to Berlin, alongside the standard chapter called "Gays and Lesbians," an extra section is devoted to "Sex and Fetish," a heading that doesn't appear in the series' guides to other cities.

"Our guides are tailored to the destinations," says the publisher. "Berlin is known for its fetish scene so we devoted a chapter to it."

Berlin earned this reputation back in the Weimar period, says Dr. Howard Hughes, formerly a lecturer on tourism at the Metropolitan University in Manchester, and author of the book "Pink Tourism," about the world of gay travel. Despite Paragraph 175 of 19th-century German law, which prohibited sexual intercourse between men, a gay and lesbian scene flourished in the city.

"You can see this in the books of Christopher Isherwood, author of 'Goodbye to Berlin,' and of course, in the musical 'Cabaret' that is based on it, both of which had a long-term influence," Hughes explains.

The queer Berlin magazine Siegessäule - named after the golden victory monument in the center of the Tiergarten - lists anywhere from a dozen to 30 gay sex parties daily. And this is just a partial list, says Jan Noll, the magazine's nightlife editor, because gay bathhouses and other places are only mentioned "when special events are being held there. There are lots of gay pubs in Berlin with dark rooms that operate daily, but we only mention them when there's a special event.

"I've lived in Berlin for 16 years," adds Noll. "A decade ago it wasn't so developed, but Berlin has really become the European sex capital and tourists come here because they have a feeling that it's wild and free. You have the legendary clubs here like Lab.Oratory and Berghain that have been around since the 1990s, and a wide range of events, but it's hard to say which came first: the legend or the tourists. It's possible that the legend drew a lot of tourists here and thus became reality. Now everyone comes to Berlin to have sex, and the sex parties are always full."

Free sex

The economic potential of all this did not escape the local tourism ministry, which markets Berlin as synonymous with sexual openness. Arm und Sexy ("Poor but sexy" ) is one of the leading tourism slogans. On the official website devoted to promoting tourism in the city, there is a page devoted to "sensual events" that lists a range of attractions, "from erotic ballet in the nude to extreme fetish clubs."

"Berlin is one of our most popular destinations, and for Israeli gays in general," says Lior Morad, marketing director of the GayWay travel agency in Tel Aviv. "They go to festivals there like Folsom, a fetish festival held every September, or to the Gay Pride Parade (every June ). The scene in the city is well established, but still perceived as avant garde. Everybody knows the Lab.Oratory, for instance, but it still has an air of mystery. And there are good bathhouses in Berlin, and lots of sex shops that specialize in fetishes."

Morad says his agency serves two types of clients. On the one hand, there are the fetishists, "a group that likes S&M, leather, master-slave, military uniforms, rougher guys who see Berlin as the focal point of the scene; there isn't much of this in Israel and it's hard to come by. And then there's the gay tourist who's sort of in the closet: People know him here where it's a small community, but Berlin gives him a refuge where he can be anonymous. San Francisco is far, Berlin is a lot closer and cheaper."

Just $400 and a four-hour flight separate the Israeli tourist from this sexual paradise. Accommodations can also be found in the city center for very reasonable prices. Unlike other sex tourism destinations that are based on prostitution, such as Thailand, here the sex is more "egalitarian," and payment is usually not involved.

"There are a lot of call girls and boys," editor Noll explains, "but I don't know anyone who comes here for the call boys, when there's plenty of free sex available all over town."

In such conditions, it's hard to talk about an exploiter-exploited dynamic, as in other instances of sex tourism (i.e., the Western tourist with a call girl/boy from an impoverished area ). What goes on in Berlin could actually be said to support the critical and subversive view of the "built-in" sexual economics of Western society. But along with this, says Prof. Eyal Gross, who lectures in law and queer theory at Tel Aviv University, "This sex culture, while it rejects conservative ideas, also creates a new norm in relation to 'what it means to be gay' ... The question is whether [this culture] creates an alternative to the social order, or whether these are again just men of privilege who can afford to travel the world and fuck other men like themselves, as consumers of plane tickets, entry to clubs, alcoholic drinks and maybe other men as well."

But gays aren't the only ones enjoying themselves in Berlin. To gain entry to the erotic club called Insomnia on Alt-Tempelhof Street, you ring the bell and hope the door opens. After you pass the test and shed any extraneous clothing in the locker room, you enter a square space that is painted red. And there you find people dancing, nice music and a laser-light show. Most of the men are dressed. Most of the women are a bit scantily clad. On Sundays, mass orgies are held here, and the price of admission varies: 80 euros for a man, 40 for a couple and no charge for women. But for the regular Saturday bash, admission is 17 euros across the board.

Things seem a little dull, but when I go to order a drink at the bar, I notice that a man's head is planted between the legs of the panty-less girl beside me. Massive curtains hide several dark spaces, where there are beds and a Jacuzzi for naked bathing, plus showers for before and after.

On the other side is a corridor with pictures of naked women lit with ultraviolet light and huge "sculptures" of female genitalia. In the corridor, a woman in a leather suit with her breasts exposed lies in a hammock. Her legs are held by chains and someone is performing a sex act on her before a curious audience of five men and two women. A middle-aged midget goes up to the upper level, holding two leather leashes attached to the neck of a tall and slender young woman who walks ahead of him. Entry into this level is restricted to couples.

Kinkier cousin

Kitkat is Insomnia's kinkier and more famous cousin. Sitting at the entrance to this club is Kirstin, who runs the place with her husband Thur. She oversees the selection process. Anyone who shows up in simple jeans and a T-shirt will remain outside.

There are two dance floors, both with oppressively loud techno music. A few young women are dancing in just their panties and bras. A naked couple is making out on the couch. Here, too, you find a big age range: a couple of Russian youths in army trousers and berets, shirtless, alongside 60-somethings sitting naked on armchairs. Some are playing with themselves, one is asleep. A man in a leather dress puts his hand on the crotch of a woman in high stiletto heels, who is kissing another man. On the walls are neon-hued paintings of men with enlarged penises and of naked women.

"At Kitkat you can do anything, as long as it's consensual. It's the sex community center," says Dr. Gadi Taub, 46, a senior lecturer in communications and p ublic policy from the Hebrew University of Jerusalem.

"Good-looking men and women, ugly men and women, gays, straights, old people, young people - it's wonderfully democratic. You go in there for the first time and you think you're dreaming. They don't need bouncers to toss people out because people respect one another, in keeping with the rules of the place: You can try anything and touch anyone - it's the local parallel to 'What's going on?' - but if he moves away from you, you don't go after him."

Taub heard about the place from a female Israeli friend and decided to check it out. "I got to meet a lot of people there and through them I got to know Berlin. It's not just random wildness. These are thoughtful people, odd birds, and the place is seductive, attractive, stimulating, surprising, bold, full of life. The clubs in Israel are quite conservative. Anyone familiar with the standards at Kitkat isn't going to fall off his chair at the sight of a little whipping and bondage."

Taub devoted the first chapter of his latest book, "Neged Bedidut" ("Against Loneliness," Yedioth Books, 2011 ), to a review of the club, and the people who run it and frequent it. "The people there have interesting things to say about sex, about love, about the tribulations of what it means to be human. There's so much talk about how it's not nice to turn someone into a sexual object, and people forget that we also have a yearning to be objectified. My position is ambivalent - that's a longing with which I empathize. Whoever tries to eliminate fetishes and S&M as a fantasy will end up getting it as reality.

"The culture has sanctified love and relates to it as an exclusively positive thing. But love is a central part of our suffering. You can never love anyone enough. It's always painful because the beloved is a separate entity and love is a desire to blend together. The Kitkat has turned the order of things inside out, and says: First sex, then we'll get to know each other. It's a euphoric thing. But it's not a solution to human despair."

Taub happened to be at the Kitkat when I visited. He stopped in Berlin on his way to Stockholm "to go to the Kitkat and see a few friends." I complained that the chapter in his book depicts the place as more lively and wilder than it really is.

"The Kitkat now isn't the same as it used to be," confirms Taub, who wrote his essay about it a few years ago. "In the past there was more action, sex everywhere, of every kind. When it was in the industrial zone, five years ago, there was a lot of S&M, more extreme stuff. It's become more establishment and predictable, repetitive. But I love the people here. It's a wonderful place. And with the number of times I come here, twice a year, you don't get bored."

Despite the pleasure, Taub says the experience offered by the Kitkat is connected to loneliness. "It's a type of extreme individualism, an attempt to take a vacation from deep personal ties. I am an object and the other person is an object. When it's just for an evening's fun, it's not such a bad thing. It's freedom from the human, not its negation. You can make it a time of feeling free from ordinary life - but not make it your life."

Which may be why for tourists from more conservative lands, the experience is a perfect part of a sightseeing trip to the city.

"For tourists it's easier to cross boundaries," notes Prof. Yuval Yanai of the University of Haifa's sociology department. "Because what you do doesn't say anything about you, it's just an experiment." Far from home, on a vacation of short duration, the locals with their strange customs become the exotic "other" and the tourist can distinguish himself from them without worrying about being identified with them or dealing with criticism.

At 3 A.M., I head over to Berghain, the city's most famous techno club. Top DJs, music that's a feast for the ears, thumping bass that really gets inside you. But it's just as famous for the long line at the entrance, the tough selection, and the fact that what happens on the dance floor, in the bathrooms and in the dark rooms is just as exciting as the music. In one room on the first floor, aside from the amazing sound, everything is more intense - especially at peak hours when it fills with gay men engaged in solo, couple or group sex and it's hard to move around without bumping into a bare chest or buttock. On the ground floor you can also find straight couples fucking. Not everyone bothers to hide; right on the dance floor there are couples and threesomes going at it in advanced stages.

For the last decade or so, the Berghain has been operating out of a power station located on the edge of the Friedrichshain-Kreuzberg quarter. The proprietors are also the owners of Lab.Oratory and at certain parties during the year (for New Year's and Easter ), the connecting door between the two spaces is opened. Then the last days of Pompeii are likely to pale in comparison. But my German friend still isn't that impressed.

"That's the difference between locals and tourists," he says. The locals are used to it all, the tourists "are keen to go back home with a souvenir. Some buy a postcard, others tell everyone how they saw people fucking at the Berghain club."

Nazi grandmothers

"Sometimes I get the feeling that the sex life in Berlin was designed to anger the Nazi grandmother," says Prof. Fania Oz-Salzberger, a historian in the law department of the University of Haifa, who specializes in Europe's relations with Israel. "The Berliners lived at the expense of the Federal Republic and scorned their parents, and part of that involved celebrating their sexual freedom and enjoying being people that the Nazis would have had executed."

Oz-Salzberger goes to Berlin three times a year. In her 2001 book "Yisraelim, Berlin" ("Israelis in Berlin," Keter ), she discusses the local sex scene and the historical "baggage" which she says is a part of the sexual contacts between Israelis and Germans - because "there is no sex without context." She says the historical dimension is connected to "a celebration of freedom that's related to the victory over the Nazis. In the 1990s, this was bolstered by the fall of the Berlin Wall."

After the unification of the city, the industrial and commercial center remained in West Germany. "What seeped into West Berlin with the fall of the wall was this nice communist social anarchism," says Oz-Salzberger. "The total secularism, the absence of a sense of sin, the sexually liberated spirit combined with the cynicism of the post-World War II era. Add to that a young culture, with virtually no responsible adult, and the city's practically extraterritorial status and the fact that the government institutions were not present in it. In recent years, the mayor, too [openly gay Klaus Wowereit] has been part of the whole thing, part of the partying young generation."

"The Germans are very liberated when it comes to sex," says Taub. "Nudity in Germany is no big deal. They strip and sunbathe in the nude in the middle of the park, and going to a (straight ) bathhouse in the nude isn't erotic at all. There's something very free about their attitude toward fetishes. But that's not to say one should envy the Nazis' heirs. A nation that lives with the feelings about what their parents did - there's something decadent and pessimistic and desperate about it. The burden that hangs over young Germans whose parents' generation committed the atrocities, leads to a pessimism that leads to hedonism. When there are no emotions, or when the emotions are too painful, you make do with thrills."

A law professor at one Berlin university, who also works as a judge and asked that her name not be cited, says that the local legal situation also contributes to reinforcing the city's status as a party city in general, and as a center for sex parties in particular. She mentions, for example, the fact that selection at the clubs is permitted and no complaints are ever lodged against clubs and bars that don't let certain people in; the legalization of prostitution; and the lack of official closing hours at clubs, which makes it possible for parties to go on until the following night. The liberal planning and construction laws have also contributed to this situation, in combination with a multitude of abandoned buildings - which results in cheap rent and lots of available space for partying, legal and illegal.

Meat market

The Kitkat club also has a side entrance, near the exit from the Heinrich Heine train station. Once a month a printed illustration of a horse is stuck on the door - the logo of the Fickstutenmarkt (the "horse-fucking market" ). Behind the slightly open door waits a muscular gentleman and an opaque black curtain that conceals what is happening within the club. The gentleman does not say a word until the visitor opens his mouth, and then he collects 10 euros and hands him a bag for his things.

This is one of the fetish parties in Berlin and it's based on the following principle: The crowd, all men, is divided into "studs" and "mares," who arrive at different times - The mares arrive about two hours earlier. They strip, and are blindfolded, and then their hands are tied and they are hitched to posts in different parts of the club. When the studs enter they can do as they like to the mares, who can only refuse with the following excuses: a penis that is too large, a penis that has a piercing, or insistence on protected or unprotected sex (mares that are ready to forgo a condom get a red blindfold, the others get white ones ).

A thick smell of sweat and sperm fills the space. The crowd is mostly older and flabby, but there also a few hunks. I almost slip on the stairs because someone tossed a used condom there. The market occasionally travels to other cities in Germany and the area, but the parties in Berlin are the main attraction, says Sasha, owner of a production company for sex events that is behind the market enterprise. (Another project, Hustlaball, draws a crowd of thousands once a year for a mass sex party. Sasha says that last year 5 percent of the online reservations for the event came from Israel. "The only other country with more reservations was Russia" ).

We meet near his office, at a gay cafe in the Schoneberg quarter, which is filled with fetish and sex shops. Sasha is 40, blue-eyed, with grayish stubble, short brown hair and a ring on his left hand.

"I started doing this five years ago,' he says quietly. "I wanted to do a gang-bang and I invented these rules just for the fun of it. Germans love rules." He published a small ad in Siegessäule and 80 people showed up, but he ended up just watching from the side. "I've never had sex at any of my parties. I'm always too pressured with organizing them."

Following that success he decided to repeat the event again, and again, until it became a monthly fixture.

The authorities have never made trouble for him in Berlin: "In other cities, yes. In Munich, for example, the police said it was against the accepted norms and the place where the event was supposed to be held was afraid to lose its license, so we had to cancel. I've also received various anonymous emails along the way, saying things like, 'Gays, go to the gas chambers,'" says Sasha, noting that the participants at his events range from "the unemployed to lawyers" and that the age "is from 20 up, with no limit."

One regular fan of the market is Guy, a high-tech worker nearing 40, from central Israel. He's been coming to Berlin for three years ("Berlin took nine measures of sex, and only one was left for all the rest of the world," he quips ). He only discovered the market five months ago, but August marked his third visit there.

"I had to come to Germany for work, so I arranged for it to fall on the date of the market," he says. "I've been all over Berlin from every possible direction, gay and straight. I learned about the horse market through the blog of somebody who had been there. There's something just so cool about this idea, so extreme. For the first time I was really in a total daze, I ran from one to the next for four hours straight, without stopping. You go in and all you have to do is choose. These places intrigue me, and it's also a way to see the city."

Screwing the Germans

And there are also those who come for the sex and stay for the quality of life. Uri, in his thirties, has lived in Berlin for six years.

"I grew up in a family of Holocaust survivors and I never planned on coming to Germany, until I was invited here eight years ago to give a talk," he explains. "At night, the students showed me the city, and what caught my attention in the gay bars was that no one looks at anyone like 'What's an 80-year-old like you doing hanging around with 18-year-olds?' And besides, there are just some amazingly gorgeous guys here.

"Ever since that first time, I kept coming back as a tourist every three or four months, and everything that I only fantasized about in Israel, came true in Berlin. It's not an arrogant nation like that of Israelis who think they can keep four million people under occupation, and where every gay man who goes to the gym for 20 minutes thinks that he's an athlete. In Israel it would be inconceivable for somebody with four-pack abs to start up with someone with six-pack abs, while I don't have any abs to speak of."

After a year and a half, Uri decided to move to Berlin for a few months, but then he met someone there and they married. He's lived there ever since. He has since divorced the fellow, but kept his residency permit and continued visiting the dark rooms in the clubs; in one of them he met his current boyfriend.

So many Israelis come to Berlin to let go, and they go crazy over the local scene and over the warm welcome. Why doesn't any of this come back with them to Israel?

Uri: "Because Tel Aviv is about the size of one neighborhood here, and because in Israel gays collaborate with the 'national erection' and suck up to the straights because they want to be part of the establishment. So they have kids and are monogamous and vote for Kadima and salute the army. And in Tel Aviv all the kind souls will also gossip about you afterward. Here the interpersonal communication is much easier, and people don't think that they're God's gift to creation."

Of course, Israelis aren't the only ones who enjoy the sexual pleasures of Berlin. Low-cost flights within Europe are making uninhibited weekends in the city more accessible than ever. But when it comes to Jewish tourists from Israel, there is also a symbolic dimension involved.

"I've often heard customers using the expression 'Screw the Germans,'" says Morad, the marketing director. "It's said as a joke, but in every joke there's a little bit of truth."

"Just as not every time that I get on the train here, do I feel like it's a transport to Auschwitz - it's not that the average German that you fuck here was a guard at a concentration camp," says Uri. "One guy, when he heard that I was from Israel, told me that his grandfather was a Nazi officer. I was sure it was going to be an amazing fuck because of all the guilt in the world, but in the end he just showed me pictures of his grandfather and went on and on about the Holocaust. I tried to explain to him that I got enough of that at home, and that I came here for a little break. But things are starting to change, and Germans sometimes view us more as sexual objects than as Hitler's victims."