Not much surprises people outside King's Cross station in London, where the new square is usually a seething mob of anxious commuters, loungers dozing off hangovers on the hard stone benches and lost foreign students.

But when what looked like the white filmy curtains of a giant shower cubicle fell and revealed a huge bronze sculpture by Henry Moore, people stopped in their tracks to stare.

"It's … yeah … different," said Raymond Van Aubel and Michell Chew, holidaymakers from Holland and Indonesia, struggling for the courteous response. "Big. We were stunned, actually."