Auschwitz was a Nazi concentration camp in Poland during World War II where over 1 million people were killed, making it a symbol of fear. It was originally built in 1940 to hold Polish political prisoners but was expanded to help carry out the "Final Solution" of exterminating Jews. Prisoners faced torture, medical experiments, and death in the gas chambers, with some camps designed specifically for mass killings using Zyklon-B gas. While the exact numbers killed are unknown due to destroyed records, it is estimated between 800,000 to over 1.1 million died at Auschwitz between 1940 to 1945 before Soviet troops liberated the surviving prisoners.