Block 11 was the name of a brick building in Auschwitz I, the Stammlager or main camp of the Auschwitz concentration camp network. The block was used for executions and torture. Between the tenth and eleventh block stood the death wall (reconstructed after the war) where thousands of prisoners were lined up for execution by firing squad. It was at Block 11 that the first attempts to kill people with Zyklon B were implemented in September 1941.