Majdanek (Lublin) was a combined work camp and extermination centre and the main killings took place there from December 1942 until September 1943. The camp was already in existence when construction of the gas chambers began in September 1942. The whole camp was closed down after the remaining inmates were killed in November 1943 in an operation called "Harvest Festival".
"Harvest Festival," there's a little cynicism for you...that's connected to Purim, I believe...the Jewish Harvest Festival.
