Berlin writer Vladimir Kaminer once called the Mauerpark ("Wall Park") a typical Berlin landmark - there's no wall, and no park. He's got a point: The Wall is long gone, and if you expect parks to feature landscaped lawns and flowerbeds, you're in the wrong city.

Occupying the site of what was once the Death Strip, the Mauerpark is little more than a narrow strip of land that spans about eight hectares, running from Bernauerstrasse in the south of the fashionable Prenzlauer Berg district to Gleimstrasse in the north. It was designated a public space in the early 1990s and has gone on to become one of Berlin's most popular outdoor haunts - despite its undeniable ugliness. In autumn, courting couples like to lie in the tall, reddish-purple fireweed that grows wild on the slopes; in winter, families go sledging down the hill that lines the central thoroughfare, and in spring, it's served for many years as one of the main hubs of the annual May 1 labor day demonstrations.

But it's in summer that the Mauerpark really comes into its own. As the days grow longer, it turns into a latter-day Woodstock: one big alfresco party that lasts until September. And everyone's invited.

A free-for-all

This year, the peaceful vibe has been disturbed by a regular invasion of teenagers, who collect here on Friday and Saturday nights to light bonfires, drink beer and, apparently, throw a few stones. The occasional fracas with the police is not unknown. In April, some 100 cops descended on the place to eject about 2,000 supposedly marauding kids after an "impromptu gathering threatened to escalate out of control," as local daily Der Tagesspiegel reported.

On Sundays, a different kind of mayhem ensues, when the Mauerpark is given over to what's become a legendary flea market, a sprawling collection of stands where you can rifle through a motley collection of retro furniture, East German tea sets, vintage sunglasses and stolen bikes.

I head into the fray one scorching June afternoon. Competing bass-lines thud from all corners of the park, and the market is packed with people flipping through second-hand records, trying on Panama hats and quaffing Caipirinhas.

At the quieter end of the park, I pass a tall, skinny guy with long hair and Jesus sandals. He’s holding up a cardboard sign that reads: "Can anyone help me get back to Canada?" Next to him, a group of 10-year-olds have set up a rickety stall selling what appear to be home-made cheese sandwiches.

Songs and games

A few games of boules are underway, and further along the thoroughfare, a group of lanky young men are playing basketball. It's an urban idyll, marred neither by the light cloud hanging over the park - a combination of pot, barbecue smoke and dust churned up by the feet of thousands of revellers - nor by the unmistakable whiff of burning flesh and kerosene. I'm reminded of a comment by local journalist Henryk M. Broder, who once wrote that in summer, Berlin parks smell like plane crashes.

By mid-afternoon, a crowd has started gathering at a concrete makeshift stage known as "the bear pit" in wait for Joe Hatchiban and his traveling karaoke machine. The Irish master of ceremonies has been a regular fixture in the Mauerpark for the last few years, and these open-air, open-mic concerts have become a major draw. The crowd is here to enjoy themselves, and the worse the performance, the louder the applause. While I'm watching, the audience generously cheer a gaggle of schoolgirls who warble their way through the Spice Girls' "Tell Me Want You Want," and are similarly indulgent when an ageing hippy gives an appalling rendition of what I guess is a made-up song that goes "Es ist verdammt schoen in Prenzlauer Berg" ("It's damn great in Prenzlauer Berg"). Obviously, they appreciate the sentiment, if not the performance.

An extreme social border

The atmosphere is bohemian and very mellow, but a lot of locals tend to avoid the Mauerpark and its crowds. A friend of mine who lives on Oderbergerstrasse, the wide, cafe-lined street that feeds into the park, told me she hadn't been there in years.

And if the Mauerpark is on your doorstep, the novelty soon wears off. These days, it's more of a tourist hotspot than a local hang-out. A row of low-budget hostels are currently under construction along Bernauerstrasse, and on an average Sunday, you'll hear more English, Spanish and Dutch than German.

But, considering that the park is right next to the neighborhood of Wedding - a district with a large immigrant population - an ethnic mix is conspicuously absent. Not for nothing did the weekly paper Die Zeit describe Bernauerstrasse a few months ago as "Germany’s most extreme social border." The only Turks you generally see in the flea market are the ones selling snacks, and most of the regular stalls are run by junk dealers from North Africa. They're definitely not taking part in Joe Hatchiban's karaoke.

The morning after

Berlin loves to portray the Mauerpark as a melting pot, but I can't help thinking that compared to London or New York, the city still has some catching-up to do on the multicultural front. And so much for the fabled live-and-let-live attitude: While I’m cycling at a snail's pace down the thoroughfare, a young woman in a Nirvana t-shirt barks at me that I should get off my bike and push it. Anarchy rules, okay?

Early the next morning I'm cycling through it again on my way to work and see a row of 10 huge skips lined up along the stage where yesterday, the karaoke singers were strutting their stuff. The weekend festivities reportedly leave some 16 cubic meters of rubbish in their wake, and a team of overalled workers are picking up the garbage strewn across the expanse of ragged, yellowed grass - cigarette packets, food wrappers and broken beer bottles.

They won't be there for much longer. According to media reports, the city has announced it can no longer afford to pick up the tab for the Mauerpark's Monday-morning clean-up.

By the time I get to the other side, I've got a puncture in my tire.

Jane Paulick cycles through the Mauerpark most days.

Editor: Kate Bowen