Jona Laks only escaped death at Auschwitz due to Nazi doctor Josef Mengele's fascination with experimenting with twins.
Seventy-five years on from the camp's liberation, she has returned with her granddaughter.
Joe Davies reports.
Sorrow and triumph, an Auschwitz survivor's journey back to a former hell
(SOUNDBITE) (English) 90-YEAR OLD AUSCHWITZ SURVIVOR JONA LAKS SAYING: "Arriving to Auschwitz, straight on the platform there was the first biggest selection, they were already, the Germans trying to get rid of the people." The road to Auschwitz.
A place Jona Laks was taken to in 1944 aged just 14.
She was lucky to come out alive.
More than a million did not.
(SOUNDBITE) (English) 90-YEAR OLD AUSCHWITZ SURVIVOR JONA LAKS SAYING: "It looked as if it was the end of the world, that everything is dark, cruel, unexplainable, inexplicable, it looked quite different." 75 years on from the Auschwitz concentration camp's liberation, Jona has returned here with her granddaughter.
(SOUNDBITE) (English) 90-YEAR OLD AUSCHWITZ SURVIVOR JONA LAKS SAYING: "Once I saw the flames coming out of the chimneys, when I got closer I could actually feel the smell of burnt flesh, only then I understood that I'm going to a place, to no good place." A year before the horrors of the Nazis' murderous regime became apparent, she arrived at Auschwitz with her twin sister Miriam and elder sister Chana.
Like all Jews, they underwent selection - some deemed fit for labour; others sent straight to the gas chambers where they were killed.
Jona's sisters were spared death but she, initially, was not.
She only survived thanks to her elder sister Chana, who begged for them not to be separated.
The selection officer that day was Nazi doctor Joseph Mengele, who subjected prisoners to pseudo-medical experiments - and had a particular interest in twins.
Jona's granddaughter peers through the window of Block 10, which served as Mengele's laboratory.
(SOUNDBITE) (English) 90-YEAR OLD AUSCHWITZ SURVIVOR JONA LAKS SAYING: "You could hear the voices, the cries of the people who were tortured, you could hear them all over." For Jona, like any survivor, coming back to Auschwitz and talking about what happened here isn't easy.
But, she says, it's important their stories are not forgotten.
(SOUNDBITE) (English) 90-YEAR OLD AUSCHWITZ SURVIVOR JONA LAKS SAYING: "We the last remaining survivors who still remain shall not, if we will not speak out and not tell, it will be forgot as if nothing happened and that's impossible."