Darkness, in the general run of things, goes well with quiet. Darkness and art, in particular, suggest contemplation and the deep inner silence of profound thoughts. But the black box that is the new installation at Tate Modern is possibly the noisiest place in London.

It would be bad enough if it was just the screaming of schoolchildren, as they discover that while Miroslaw Balka’s 100ft steel box is meant to evoke feelings of disorientation and helplessness, it actually makes a splendid space to run up and down, shouting at the top of your voice.

However the most disturbing sound today, the first day his installation How It Is was open to the public, was the resounding clang as Giles Crosthwaite walked smack into the end wall without putting the brakes on. That is the problem with walking around in the dark; you cannot see where you are going. “I thought it went on further,” said Mr Crosthwaite, 36, rubbing his forehead in a rueful manner. “We were just chatting. I didn’t realise that the wall was there. I’m probably going to have a bruise in the morning.”

Perhaps he should have adopted the technique used by Flora Susskind, a drama teacher from Brazil whose progress towards the end wall slowed almost to a halt as she gingerly moved forward inch by inch, stretching out her foot to make sure nothing terrible befell her. What was she worried about? A step? A hole? A pit full of snakes? “I was afraid it went down,” she said. “I thought it would be something like Alice Through the Looking-Glass. I was quite afraid.”

Somewhere between the impetuosity of Mr Crosthwaite and the caution of Ms Susskind was a sensible middle ground, which consisted of walking at a steady pace with one’s hand stetched out until it encountered the steel wall, which has been covered with an absorbent flock coating. “Ooh it’s soft,” said one woman. Several, actually. “Ooh, it’s furry,” said another. “I enjoyed that.”

The terrible truth was, however, that the box is not really that dark, not with the entrance being completely open (and don’t even mention the camera flashes, or the glow of the mobile phones). Hang around there for more than a couple of minutes and the darkness becomes, if not light, then at least a perfectly serviceable gloom.

“I’ve been down a few pot-holes,” said Frank Iles, 62, from Rochester, Kent. “When you reach your target, turn off your light and eat your Kendal mint cake — THAT’S total darkness.”

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