On 13 August 1961, East Germany closed its border between East and West Berlin, dividing Berlin for the next 28 years until the fall of the Berlin Wall on 9 November 1989.
The 50th anniversary is a sobering commemoration.
The Wall was a 1962 short documentary film directed by Walter de Hoog for the US Government
See BBC News and France24/AFP for reporting on the commemorations (in English).
More in-depth coverage in Deutsche Welle (in English), Die Welt, Berliner Morgenpost (2) and Der Spiegel.