Dark haired couples in passionate clinches sliding sensually across a dance floor, looking intense and a perhaps just a little erotic – that was the image in my head as I headed for my first ever milonga, or social tango dance.

But while the atmosphere was intense and brooding, the mixed bag of people completely confounded my cliché. Dancers of all ages, backgrounds and skill took to the streets to tango.

The pretty little Plaza Dorrego in Buenos Aires’ historic San Telmo sets the perfect backdrop for this dramatic dance. Held every Sunday, after the vast antiques market has been cleared away and the sun has set, scores of dancers slide across the makeshift dance floor, between grand colonial buildings and across cobbled streets.

Even though the tango has long been undergoing a renaissance in Argentina, with a newly infused generation of dancers reigniting the old tradition, I didn't expect to find the range of people who were willing to bare all on the dance floor. A young hippy couple, wearing tango shoes with their ripped surfer shorts, were dancing as expertly as two old seasoned Argentines next to them.

Amid the dense night air, over 40 couples clasped their bodies together, and moved with the wide sweeps, and little kicks that define this dance.

The tango first started in Buenos Aires, and watching it in San Telmo, the bohemian heart of the city, you felt like someone may have taken the very first tango steps right at your feet.

Earlier in the evening, while stalls are still being dismantled from the market, you can watch a couple do a street tango show. While this is a very flashy type of tango danced for spectators, it is completely mesmirising. There are leaps, abrupt changes of direction, jumps and lifts. With his cheek almost touching hers, he leads her around the dance floor, controlling her feet with the smallest signals. It is this chemistry that is so beautiful, and yet makes the tango so illusive to grasp.

Just two days earlier, I took my first tango class with the fabulous Viviana Parra and Mariano Pedernera, a married couple who ooze so much sex on the dance floor, you never want them to stop dancing. At first they just teach you to move around the class, understanding how to hold your body, how to feel the floor, and how to hear the music. But by the end of our one-hour group lesson, everyone is doing at least a make-shift tango.

The onus is on the men who not only have to improvise the steps, stay in time with the rhythm but also communicate silently with their partner. As a girl, with a good partner, you barely need a lesson. The few steps I danced with the instructor Mariano, was like magically being endowed with the gift of dance. In his arms, I moved elegantly across the floor, without a glance at my feet. But back to reality and an amateur partner, I was stepping on toes and even kicking myself in the chin.

For a beginner like me milongas can be a little intimidating. And at the San Telmo milonga many of the 10,000 visitors, who descend on the barrio every Sunday for the famous antiques market, stay during the evening to watch the spectacle. The less confidant tango dancers hide behind the crowds, where they can still hear the fantastic live band while stepping on each others' feet and giggling without disturbing the dance.

And for anyone with two left feet, life doesn’t get much better than sipping a glass of local Malbec while sat on a balcony of one of the handful of bars overlooking the square, breathing in the bohemian atmosphere and watching the graceful dance below.