The house, until this year, had always been in private hands. A U.S.-based group, the "Counter Extremism Project," has purchased it. Now, in conjunction with the Auschwitz Museum and UNESCO, they have created "The Auschwitz Center on Hate, Extremism and Radicalisation." The home is now open to the public for the first time.

In just over four-and-a-half years, Nazi Germany systematically murdered at least 1.1 million people at Auschwitz, built in the south of occupied Poland near the town of Oswiecim. Auschwitz was at the centre of the Nazi campaign to eradicate Europe's Jewish population, and almost one million of those who died there were Jews.

In all, 56 survivors gathered under a huge tent on Monday set up over a gate and railway tracks at the site of the former camp.

“God suffered a great deal in every single person who was here. God suffered a great deal in this place,” Cardinal Rys added.

World leaders rubbed shoulders with 56 survivors of Hitler's death camp as they marked 80 years since its liberation.

It doesn’t do any good for your heart, for your mind, for anything,” said Holocaust survivor Jona Laks, 94, about her return to Nazi Germany’s Auschwitz-Birkenau concentration camp.

Survivors of the Nazi's notorious Auschwitz death camp are taking center stage at the memorial service to mark 80 years since its liberation by Soviet troops.

Auschwitz survivors have warned of the rising antisemitism and hatred in the modern world as they gathered with world leaders and European royalty on the 80th anniversary of the death camp’s liberation.

By Barbara Erling and Kuba Stezycki OSWIECIM, Poland (Reuters) -Auschwitz survivors were being joined by world leaders on Monday to mark the 80th anniversary of the liberation of the Nazi German death camp by Soviet troops,

The ceremony is widely regarded as the last major observance likely to see a significant number of survivors in attendance.

In all, the Nazi regime murdered 6 million Jews from all over Europe, annihilating two-thirds of Europe's Jews and one-third of all Jews worldwide. In 2005, the United Nations designated Jan. 27 as International Holocaust Remembrance Day.