Life, they say, is all about timing. It's just a shame that my timing is so rubbish.

On November 9, 1989, the world watched agape as grinning East Germans clambered over that symbol of communism made concrete - the Berlin Wall. But in a classic case of bad timing, I missed the historical event by a few months, turning up when much of the imposing structure had been consigned to the souvenir pile of history.

Fast-forward two decades and I still can't get it right, arriving in Berlin a month too early for the 20th anniversary celebrations to mark the end of the world's only border fortification built to keep people from leaving, rather than to protect them.

But no matter when you visit this city, the Wall's history tugs at you. These days, Berlin looks to the future as much as to the past, but there are few places on Earth where the two are so inextricably linked.

Briton Nick Gay, who runs Berlin Walking Tours, says that for a long time the city fathers showed little interest in preserving what was left of the Wall.

"For almost 30 years, Berlin suffered under one of the greatest geographic and political anomalies of all time - a city split in two by a concrete wall which tore apart families, friends and lovers, and resulted in the death of at least 136 people who tried to cross the divide. Because so many stories connected to the Wall involved horrific suffering, there was an initial rush to obliterate this symbol of political oppression."

But as the pain has receded, the city has acted to remind both locals and visitors of the defunct border.

Berliners have reclaimed 18 sections of the Wall, along with rusting guard towers and other chunks of Cold War debris. You can, for example, follow a trail of cobblestones through the city that plots the course of the so-called Hinterland Wall, a precursor to the Wall itself, which is linked by a 14km cycle trail.

Sadly, the fact that it's too cold - and I'm a wuss - means I forego biking for the much warmer Berlin Wall Video Bus Tour. The tour splices original film and TV footage with old black-and-white photos to bring history to life as you criss-cross the vibrant capital's streets. One of the most poignant moments comes when we stop at the official wall memorial, Gedenkstatte Berliner Mauer, which traces the exploits of 57 East Berliners who overcame enormous odds to tunnel to the West and much-longed-for freedom in 1964.

Yet it's a humble pensioner who provides the most poignant taste of what so many East Germans were literally dying to get away from.

By chance, I stumble upon 69-year-old Jurgen Litfen sitting on a stool outside a former watchtower near the Humboldthafen dock. One of 302 towers that once encircled East Berlin, the imposing structure was rescued by Litfen from demolition more than a decade ago when he turned it into a memorial and mini museum.

Litfen's watchtower is dedicated to his brother Gunter, a 24-year-old tailor shot by police on August 24, 1961 as he attempted to swim to freedom - the first person killed while trying to defy the then 11-day-old wall.

"Gunter had no idea the border patrol had orders to shoot," says Litfen, who admits his tours help him cope with the still-visible grief of losing his brother.

"This memorial keeps alive the memory of the crimes committed at the wall. To forget would be the worst thing - we need to remember our history so that it can never be repeated."

Bisecting the formerly sliced-up metropolis is Potsdamer Platz, which once served as a desolate death strip. But when relations thawed after almost 30 years of political deep freeze, some of the world's largest corporations moved in, turning the area into a gleaming glass-and-steel shrine to capitalism.

Turn your back on the soaring atrium of the Sony Centre and you'll find yourself at the Topography of Terror. This free, open-air exhibition uses stark black-and-white photos and actual documents to illustrate both the inhumanity of the border and how it was overcome. The fates of both the perpetrators and the victims are included in the exhibit which is incongruously housed in a humble trailer (a new centre is under construction). The site once served as the Nazi Reich Security Office and Gestapo torture cells, and still features around 200m of the wall.

A short ride away on the super-efficient U-Bahn is the new, interactive DDR Museum, which features a chilling example of what life must have been like under the Nazi regime. We learn about collective potty breaks for kindergarten students, barbarous experiments on those considered a threat by the secret police, and anabolic steroids given to potential athletes as young as 5. Then there is the authentic Trabant, the notoriously unreliable car that was coveted by thousands of Berliners who often had to wait more than 10 years to get one - then spent a lifetime dealing with constant breakdowns.

A cold wind is blowing across the River Spree when we head to the celebrated East Side Gallery, where the largest remaining section of the wall makes history tangible. In 1990, 118 artists from 21 countries covered this 1.3km stretch of concrete with graffiti and murals. Almost $2.5m was recently spent tarting it up in preparations for the 20th anniversary "freedom festival" celebrations, which include exhibitions, an open-air concert and the symbolic tumbling of a 2km wall of dominoes. Shame I'm too early to see it.

Sharon Stephenson travelled with the assistance of Singapore Airlines and Top Deck.