Auschwitz-Birkenau was the largest Nazi concentration and extermination camp, where over 1.1 million men, women and children lost their lives during WWII. The Auschwitz-Birkenau State Museum was created by an act of the Polish Parliament in July 1947. Several hundred camp buildings and ruins stand on the 191-hectares museum grounds, including the ruins of the gas chambers and crematoria and over a dozen kilometres of fence.