Explore the dark past of Germany’s capital city Berlin

WHAT would the Stasi make of taking a selfie and sticking it up on Facebook?

We all do it these days yet in the former East Berlin this simple act takes on a grim irony.

The secret police spent 40 years spying on its citizens.

But they wouldn’t need to bother now – people happily post their private lives online for the world to see.

If you want a taste of life behind the Berlin Wall, visit the forbidding Stasi HQ, now a museum, where tyrant boss Erich Mielke’s office has been preserved.

It is a world of Bakelite telephones, switchboards with oversized buttons, tape recorders, typewriters — and paper shredders.

When the Wall came down in 1989, East Germans stormed the building, demanding to see what the Stasi had on them. Panicked officials frantically started shredding files.

But not quickly enough. Some 140km of dossiers on six million people were discovered.

The Stasi’s mission was to stifle any dissent that might threaten the East German Socialist “utopia”.

Discover just what that utopia was like at the brilliant DDR Museum.

Displays recreate the dismal world of surveillance, rationing, poverty, fear and relentless propaganda — all soundtracked by terrible “official” pop music.

No wonder so many risked being shot while escaping over the Wall to the West.

Checkpoint Charlie, one of the crossing points, is still there and is arguably Berlin’s most famous sight.

Today it is very touristy, with actors dressed as border guards, hamming it up for foreigners’ selfies.

But the museum next door gives you a good idea of the ingenuity of the escape plans and the bravery of those fleeing.

One of the best ways to see Berlin is to follow the Mauerweg — the route of the Wall — a double-brick line that zigzags across Berlin showing where it stood.

Parts are still standing, such as the East Side Gallery where in the heady days after the fall, graffiti artists daubed the Wall in slogans and cartoons celebrating freedom.

Last week there was cause for more celebration. The Wall has now been down some 10,300 days — as long as it stood dividing the city.

It can take a while to get your bearings in Berlin. Despite reunification, the city has three distinct centres.

Kurfürstendamm is the wealthy capitalist centre of West Berlin, full of posh restaurants and shops such as the massive department store KaDeWe (definitely worth a visit).

Potsdamer Platz was levelled by Allied bombing, cut in two by the Wall then left as a rubble-strewn No Man’s Land for three decades before being rebuilt as a gleaming steel and glass commercial centre.

Alexanderplatz was the heart of the old East where every May Day, thousands of soldiers and tanks would showcase the power of the Socialist regime.

Today, most vehicles sweeping past its brutalist architecture are the hop-on, hop-off tour buses — a great way to find your way around.

Blitzed by Allied bombers then ransacked by the Red Army, Berlin was rebuilt by rival capitalist and communist town planners desperate to destroy the Nazis’ legacy.

Berlin is candid about this dark period.

The site of the Gestapo HQ is now the Topography Of Terror museum, a jaw-dropping history of Nazi persecution.

Nearby is the Holocaust Memorial, a maze of 2,000 stark grey columns that close in over your head, symbolising growing unease, powerlessness and, ultimately, terror.

The memorial is a stone’s throw from a car park that wouldn’t normally merit any mention.

Here, now tarmacked over, was the bunker where Hitler killed himself in 1945.

There is no plaque just a small, sober explanatory notice.

As a reaction to this traumatic history, Berlin has long been Europe’s party capital, drawing pleasure seekers like David Bowie, and Iggy Pop.

Today, young Brits flock to the edgy bars and clubs to soak up the tolerant, anything-goes vibe.

If edginess isn’t your thing, walk through the tranquil Tiergarten park.