Alain Resnais's Nuit et brouillard | Night and Fog (1955)

Nuit et brouillard comes from the German name given to the deportees to the concentration camps, NN (Nacht und Nebel), the oblivion of night and fog. The screenplay of this short is by Jean Cayrol, who survived Mauthausen, and the footage is black and white archival, and (then) presentday colour of the remains of the Holocaust. In a sense, it's a forerunner to Claude Lanzmann's monumental nine-hour Shoah (1985), which is largely a great number of accounts of people's experiences of the Holocaust, without archival footage. Arguably, Resnais's film is more harrowing as it shows the starving Jews, the murdered Jews kicked into pits, the use of dead Jews' hair to make mats, of their skin to make a kind of paper to draw on, of their bodies to make soap, and on and on. Along with Lanzmann's film, this should be compulsory viewing, so that we never forget the atrocities perpetrated by the Nazis, so that such obscenities never happen again.