View of the Majdanek "death camp" (1944) 
"Majdanek was a German Nazi concentration camp on the outskirts of Lublin, Poland, established during German Nazi occupation of Poland. The camp operated from October 1, 1941 until July 22, 1944, when it was captured nearly intact by the advancing Soviet Red Army. Although conceived as a forced labor camp and not as an extermination camp, over 79,000 people died there (59,000 of them Polish Jews) during the 34 months of its operation." 
The United States Holocaust Memorial Museum claims that "tens of thousands of jews" were murdered at Majdanek, many with Zyklon B in gas chambers:
"In the winter of 1941-1942, camp authorities began to use Zyklon B gas to murder prisoners too weak to work in a makeshift gas chamber. Mass murder operations using poison gas began at Majdanek in October 1942 and continued until the end of 1943. There appear to have been three gas chambers at Majdanek; at least two were shower rooms reconfigured for use of Zyklon B gas. At least one of these two was used to kill human beings. Some sources refer to a third gas chamber, which reportedly used carbon monoxide gas as a means of murder."
- United States Holocaust Memorial Museum
So what of that original alleged 1.5 million number?
source: Winston Smith Ministry of Truth
It's now claimed around 79,000 people were murdered by the Nazis in Majdanek extermination camp. The figure was once much, much higher:
"About 1,500,000 persons were exterminated in Maidanek"
- Nuremberg Trial Proceedings - Indictment : Count Three (see approximately 20% down page for quote)
Unlike the 4,000,000 original figure for Auschwitz details the Majdanek 1,500,000 figure can't be dismissed as a Soviet exaggeration, because it was a Canadian journalist in the pay of Canadian Jews who claimed it.
On the 29th August 1944 a telegram was received by Saul Hayes, the executive director of the Canadian Jewish Congress, it reads:
"[An] unexampled destruction opened before my eyes as I walked about Majdanek at Lublin [the] day before yesterday ... There is no doubt that Majdanek will go down into history as one [of the] most horrible experiences in mankind ... I do wish [to] stress that Majdanek where one million Jews and half a million others [were] killed calls for justice [and] for revenge and [the] world can't be satisfied until it is revenge obtained ... I saw partly burned bodies their arms and legs chopped off to make [it] easier pushing into ovens and I saw great mountain grey urns Germans used to collect ashes ... You can tell America that at least three million [Polish] Jews [were] killed of whom at least a third were killed in Majdanek"
- "Delayed Impact: The Holocaust & the Canadian Jewish Community" by Franklin Bialystok
A Majdanek "Bath and Disinfection" complex (aka "Gas Chamber I") 
The Majdanek delousing chamber. Note the unbarred window in the upper left corner .
- "The 'Gas Chambers' of Auschwitz and Majdanek" by Germar Rudolf
- Institute for Historical Review: "Majdanek Gas Chamber Door Fraudulently Portrayed at U.S. Holocaust Museum"
- "A Revisionist Monograph on Majdanek" by Jürgen Graf and Carlo Mattogno
- Holocaust Education and Archive Research Team article on Majdanek
- Scrapbook Pages article on the Majdanek "gas chambers"
- Photos of Majdanek
- The Majdanek Gas Chamber Myth (Documentary film)