Behind Dr Gabriele Gauler, a confused and tense crowd stands frozen. Young, old they stand, perch and clamber onto a graffiti-covered wall lit by harsh floodlights on a dark night. The crowd is nervous, unsure of whether to believe the explosive news: East and West Berlin would no longer be divided. 'For Germany it was a lucky end,' says Gauler, the new director of the German Goethe-Institut in Hong Kong, gesturing at the photo of that historic night in November 1989 when the Berlin wall came down. 'Nobody could expect this.' Yesterday Germany's reunited capital marked the 50th anniversary of the day the Berlin Wall started to go up with a memorial service and a minute of silence in memory of those who died trying to flee to the West. In Hong Kong, the Goethe-Institut, a non-profit German cultural body, is showing the exhibition 'Scenes and Traces of a Fall', bringing together the works of eight photographers who documented the breakdown and gradual disappearance. They show the wall as it was - imposing and deadly. The drama of its last days - the media circus, politicians' speeches and its demise - being torn and hammered down by ordinary people. And finally, the few traces that remain now of the greatest symbols of a divided Europe after the second world war. The Wall was born in the early hours of Sunday August 13, 1961, to stop the exodus of East Germans fleeing the Soviet-occupied East. In a secret operation, tens of thousands of East German soldiers and factory militiamen blocked streets, cut rail links and began building a wall of barbed wire and cemented paving stones, which over the years grew to be over 155 kilometres long. For Gauler the pictures are particularly evocative. She was born the year the wall went up, and was 28 when it fell. 'It was a depressing thing to visit East Germans,' she says. 'The military was very strict. The people who were guards at the frontier, they had to shoot when someone behaved strangely. There was no pardon.' Nowadays in most parts of Germany, there's only the faintest hint that there might have once been something there. 'In this series, you can only see the traces,' says Gauler. She's looking at a series of photographs by Thierry Buignet of vacant lots and dilapidated buildings scattered with overgrown vegetation. It's a reminder of how quickly things can be forgotten. The wall for many young people in Germany, she says, is often the same kind of hazy memory these photographs conjure. But the wall was real, and Gauler says, and it means more than a mere history lesson. 'There are of course other countries what have a wall. Look at Korea for example. Cyprus also still has a wall.' The exhibition, which opened in Berlin October 2009 finishes in Hong Kong on September 17 and moves to Bandung, Indonesia.