This year sees the 25th anniversary of the fall of the Berlin Wall. From 1961 to 1989, the city of Berlin was divided by the most visible sign of the Cold War: a barrier more than 140km (87 miles) long.

Construction of the Wall began on 13 August 1961, isolating capitalist West Berlin within Communist-controlled East Germany.

Berlin Wall fall: 25th Anniversary
13 August 1961: Soldiers begin building the Berlin Wall, as instructed by the East German authorities, in order to strengthen the existing barriers dividing East and West Berlin. (Getty)

On 15 August 1961, during the early days of the Wall's construction, East German border guard Conrad Schumann jumped over the barbed wire barrier into West Berlin. It is thought that around 5,000 people successfully defected to the West by risking their lives to cross the Wall.

The number of people who died trying to escape is under dispute. Alexandra Hildebrandt, Director of the Checkpoint Charlie Museum, estimates the death toll to be well above 200, while the Centre for Contemporary Historical Research in Potsdam has confirmed 136 deaths.

The first Berlin Wall casualty was Ida Siekmann, who died after she jumped out of her third-floor apartment at 48 Bernauer Street on 22 August 1961.

Günter Litfin was the first person to be shot whilst attempting to escape across the Berlin Wall. The 24-year-old tailor was spotted while trying to swim across the Spree Canal to the West on 24 August 1961.

Many methods of escape were successfully used by East Germans desperate to escape to the West, including tunnels, hot air balloons, zip wires, and ultralight aircraft.

In 1964, Wolfgang Fuchs built a tunnel that enabled more than 100 East Germans to reach the West. Another tunnel began in an East Berlin cemetery. "Mourners" brought flowers to a grave and then disappeared. This route worked well until Communist officers discovered a pram left by the "grave" and sealed the tunnel.

Berlin's Checkpoint Charlie Museum displays several vehicles that were modified to smuggle defectors across the border.

The number of escapes led to the East German authorities strengthening the Wall.

In its final form, the Berlin Wall consisted of inner and outer concrete walls separated by a "death strip" lined with fences, trenches and anti-tank fortifications, with searchlights and guard towers positioned along the route. The barrier was guarded by troops authorised to shoot anyone who tried to escape.

The last person to be shot and killed while trying to cross the border was Chris Gueffroy on 6 February 1989.

In 1987, US President Ronald Reagan addressed the people of West Berlin at the base of the Brandenburg Gate. His call of "Tear down this wall!" could be heard on the Eastern side of the wall. The speech is considered by many to have affirmed the beginning of the end of the Cold War and the fall of Communism.

In January 1989, then-East German leader Erich Honecker declared that the Berlin Wall could stand for another century. But increasing freedoms in the Eastern Bloc led to more porous borders and to demands to tear the Wall down. Honecker resigned on 18 October 1989.

On 9 November 1989, East German authorities announced they would allow free access between East and West Berlin. Crowds of euphoric East Germans crossed and climbed onto the wall, leading to a reunited Germany.

Berlin Wall fall: 25th Anniversary
12 June 1987: US President Ronald Reagan, commemorating the 750th anniversary of Berlin, addresses the people of West Berlin at the base of the Brandenburg Gate. "Tear down this wall!" was the famous command from Reagan to Soviet leader Mikhail Gorbachev. (AFP)