Pope Benedict XVI had insisted on visiting Auschwitz. He walked alone through the camp gate, under its infamous sign reading "Arbeit macht frei" (Work makes you free).

A former Auschwitz prisoner, Michnol Jerzy, shows pictures of his parents as he walks through the camp. Pope Benedict was greeted by 32 former inmates during his visit.

The Pope said a prayer in front of the execution wall, watched the survivors who had returned to the camp to meet him. The Nazis killed thousands of inmates at the wall.

Emotion grips Cardinals Jean Marie Lustiger (l) and Joachim Meissner as the Pope prays in courtyard 11 of the former Auschwitz death camp.

At Birkenau, the Pope walked along a row of 22 tablets in front of the memorial to victims. Each tablet represents a different nationality of those who died at the camps.

As he prayed in front of the Birkenau memorial, watched by a 500-strong crowd, a rainbow appeared in the sky.

The Pope said a prayer for peace in his native German tongue. He said it was particularly difficult for a Christian, and a German pope, to speak from a place of such horror.