The Berlin Wall as it is usually pictured did not appear overnight.
However, just after midnight on Sunday 13th August 1961 the East German army began to close the border with West Berlin.
East German troops and workers began to tear up the streets which ran across the border to make them impassable and to add barbed wire entanglements along the 156 kilometres around the three western sectors and the 43 kilometres that divided West and East Berlin.
The initial closing of the Berlin border used barbed wire fencing
The first concrete components and large blocks began to be added from the 17th August 1961 and the familiar shape of the Berlin Wall began to appear.
During the construction of the Wall, soldiers stood close by with orders to shoot anyone who attempted to defect.
Great care was taken to ensure that the Wall did not encroach on West Berlin territory......and access to the western side of the wall was possible from the east
In the image above, East German soldiers are guarding both sides of the Wall.
At the same time, improved chain fences, walls, minefields and other obstacles were installed along the length of East Germany's border with West Germany.
The barbed wire of the earlier 1952 border is visible in the foreground with the improved barriers and defences behind
The old (pre-1949) terminology of "Zone Border" (Zonengrenze) can be seen on the sign
A video of still images showing the building of the Berlin Wall with the DDR's national anthem.