The outside door at this far end is a definite fake. It is made of masonite, unlike the other three doors, it opens outwards, and has a round porthole. We know that this door has been altered three times by referring to various Auschwitz guide books over the years. There are nine horizontal wooden slats in this original door, and no porthole. This door had an iron bar added to the upper part of the door, plus a square porthole.
Confusion reigns here again.
A model of Birkenau which is on display at Auschwitz a couple of miles away transposes many of the rooms. Unfortunately, it is not possible to totally check these allegations forensically, since the Germans are supposed to have blown up the business part of all the Birkenau gas chambers shortly before the camp was evacuated in 1945. The entire building of Crematory 4 has disappeared except for the foundations. Crematories 2 and 3 are partly destroyed, but there still remain a couple of buildings which I was able to explore inside. There is no trace whatsoever of any furnaces, chimneys, sliding doors, screwlids, perforated sheetmetal columns, electric lifts, or any other Holocaust props.