PowerPoint Show by Andrew

This weekend, Germany will observe the 25th anniversary of the fall of the Berlin Wall. The German Democratic Republic (East Germany) began erecting the barrier in 1961, building on existing checkpoints, and fortified it over nearly 30 years:

The initial waist-high wooden gates gave way to massive concrete structures with buffer zones known as "death strips." The Berlin Wall was intended to halt the steady stream of defections from the Eastern Bloc; during its existence, only about 5,000 people managed to cross over, escaping into West Berlin.

More than 100 are believed to have been killed in the attempt, most shot by East German border guards. In 1989, waves of protest in East Berlin and a flood of defections through neighboring Hungary and Czechoslovakia led the government to finally allow free passage across the border. West German citizens swarmed the wall, pulling parts of it down with hammers and machinery, an act that set the stage for Germany's reunification.

On August 13, 1961, East Germany closed its borders with the west. Here, East German soldiers set up barbed wire barricades at the border separating East and West Berlin. West Berlin citizens watch the work.

A young East Berliner erects a concrete wall that was later topped by barbed wire at a sector border in the divided city August 18, 1961.

Tracks of the Berlin elevated railroad stop at the border of American sector of Berlin in this air view on August 26, 1961. Beyond the fence, communist-ruled East Berlin side, the tracks have been removed.

In center of the Bornholmer Bridge steel tank traps were constructed with a big sign showing the East German emblem hammer and compass.

East German VOPO, a quasi-military border policeman using binoculars, standing guard on one of the bridges linking East and West Berlin, in 1961.

Under the eye of a communist "people's policeman", East Berlin workers with a power shovel destroy one of a number of cottages along a sparsely settled stretch of the east-west Berlin boundary in October of 1961.

A young girl in the Eastern Sector looks through barbed wire into Steinstucken, Berlin, in October of 1961.

Blocking the church - Two East Germans work on a huge 15 foot wall, placing pieces of broken glass on the top to prevent East Berliners from escaping.

A refugee runs during an attempt to escape from the East German part of Berlin to West Berlin by climbing over the Berlin Wall on October 16, 1961.

Typical of East Berlin measures to halt the escape of refugees to the west are these bricked-up windows in an apartment house along the city's dividing line October 6, 1961.

East Berlin laborers work on "Death Strip" which communist authorities created on their side of the border in the divided city on October 1, 1961. A double barbed wire fence marks the border, with West Berlin at right.

East German border guard Conrad Schumann defected by leaping into the French Sector of West Berlin over barbed wire on August 15, 1961.

View from top of the old Reichstag building of the Brandenburg Gate, which marks the border in this divided city. The semi-circled wall around the Brandenburg Gate was erected by East German Vopos on November 19, 1961.

The Brandenburg Gate is shrouded in fog as a man looks from a watchtower over the Wall to the Eastern part of the divided city on November 25, 1961.

Dying Peter Fechter is carried away by East German border guards who shot him down when he tried to flee to the west in this August 17, 1962 photo. Fechter was was taken to a hospital where he died shortly after arrival.

Reverend Martin Luther King, American civil rights leader, invited to Berlin by West Berlin Mayor Willy Brandt, visits the wall on September 13, 1964.

A mass escape of 57 people in October 1964 from East Berlin through a tunnel to the cellar of a former bakery in "Bernauer Street", West Berlin.

West German construction workers have a chat in West Berlin, April 18, 1967 beside the wall separating the city.

Picture taken in June 1968 of the Berlin Wall and East Berlin (Soviet sector).

East German border guards carry away a refugee who was wounded by East German machine gun fire as he dashed through communist border installations toward the Berlin Wall in 1971.

Aerial view of Berlin border wall, seen in this 1978 picture.

A woman and child walk beside a section of the Berlin Wall.

A graffiti-covered section of the wall close to the Brandenburg Gate in Berlin in 1988. Sign reads: "Attention! You are now leaving West Berlin".

West Berlin citizens hold a vigil atop the Berlin Wall in front of the Brandenburg Gate on November 10, 1989.

(1 of 3) Two East Berliners jump across border barriers on the Eastern side of border checkpoint at Chaussee Street in Berlin in April of 1989.

(2 of 3) Two East Berlin refugees are taken away by border guards after a thwarted escape attempt at Berlin border crossing.

(3 of 3) An East Berlin border guard, cigarette in mouth, points his pistol to the scene where two East Germans were led away after failing to escape to the west.

A view of the overcrowded East Berlin Gethsemane Church on October 12, 1989. About 1,000 East Germans took part in a prayer service here for imprisoned pro-democracy protesters.

An unidentified East German border guard gestures toward some demonstrators, who threw bottles on the eastern side of newly-erected barriers at the Checkpoint Charlie crossing point on October 7, 1989.

East and West Berliners mingle as they celebrate in front of a control station on East Berlin territory, on November 10, 1989, during the opening of the borders to the West following the announcement by the East German government that the border to the West would be open.

East Berliners get helping hands from West Berliners as they climb the Berlin Wall which divided the city since the end of World War II.

A man hammers away at the Berlin Wall on November 12, 1989 as the border barrier between East and West Germany was torn down.

West Berliners crowd in front of the Berlin Wall early November 11, 1989 as they watch East German border guards demolishing a section of the wall in order to open a new crossing point between East and West Berlin.

East and West German Police try to contain the crowd of East Berliners flowing through the recent opening made in the Berlin wall at Potsdamer Square, on November 12, 1989.

Decades later, the Berlin Wall is a memory, pieces of it scattered around the world. Here, some original pieces of the wall are displayed for sale at the city of Teltow near Berlin, on November 8, 2013.