U.N. Secretary-General Ban Ki-moon on Monday visited the former Nazi death camp of Auschwitz to pay tribute to Holocaust victims.

Ban walked through the infamous "Arbeit Macht Frei" (Work Makes You Free) gate to see exhibitions that document the inhuman conditions that the inmates suffered there.

Housed in red brick barracks, are the hair and belongings of the inmates, as well as an urn symbolically holding some of the victims' ashes.

Ban laid flowers at the executions wall, where thousands of inmates, mostly Polish resistance members, were shot. He then went to nearby Brzezinka, with its crematorium ruins and a monument to the victims. Ban was also to visit the Chevra Lomdei Mishnayot synagogue, the only remaining building that testifies to the pre-war vibrant Jewish life in the town of Oswiecim.

Between 1940-1945, some 1.1 million people, mostly Jews, died in gas chambers or from starvation, disease and forced labor in Auschwitz and the adjacent Birkenau death camp that Nazi Germany built in occupied Poland.

Ban also visited Krakow, 50 kilometers (31 miles) from the Auschwitz memorial. On Tuesday he will join a U.N. climate conference in Warsaw.

Boutros Boutros-Ghali was the first U.N. secretary-general to visit Auschwitz in 1995.