The Rain Room – an interactive installation involving an indoor downpour – is currently running at London’s Barbican Art Gallery to critical acclaim. As a result, the free show – which runs until 3 March 2013 – is drawing huge crowds on a daily basis. But in a city known for its year-round drizzly weather, why are people waiting in line for more than two hours to experience more rain?

To start with, you don’t get wet in the Rain Room. Once you enter the dark space where a dramatic spotlight shines on a 100sqm patch of falling water, the sound of the shower and the feeling of moisture in the air immediately gives the familiar impression of being caught in a downpour. But unlike a regular rainstorm, the water above your head stops as you move though it, allowing the audience to feel as though they are controlling the weather.

At first, small groups of people move slowly and cautiously into the heavy shower, testing the mechanics of the installation with a hand, an arm and finally their whole body. As confidence builds and the audience realises they won’t get soaked, adults and children alike can be seen performing a joyful dance under the rain.

Random International, the contemporary art group behind the show, is known for experimental works that often require audience participation. The group designed the Rain Room to push visitors outside their comfort zone and see how people would react when faced with a different outcome to an all too familiar situation.

Is it worth the wait? Yes. The build-up adds to the experience and heightens curiosity.  If you were to walk straight in from the streets of London where, let’s face it, it is more than likely to be raining, the delightfully surreal quality of the Rain Room might seem just a bit too – real.

Malika Dalamal is the London Localite for BBC Travel