Nuremberg was a show trial.

The court took "judicial notice" of all proceedings and findings of Allied countries including the Soviets (see Article 21 of the Internal Military Tribunal Charter) which meant that the findings of Soviet show trials were taken as irrefutable evidence; the defense was not even allowed to challenge them.

https://www.refworld.org/docid/3ae6b39614.html

Moreover the Nazis were tortured & leapt to incriminate themselves. Part of the preparation for the IMT was mock trials in which denial of guilt met a death sentence but confessions met leniency.

It shouldn't need to be said but none of this is to promote Nazism, gulags (which is what the concentration camps were), or war (which is mass murder). I personally am an anti-socialist libertarian & more Jew than German. But I love the truth more than I hate Nazis.

The gas chamber at Auschwitz was "restored" (fabricated) by the Poles after the war ended. The famous Western photos of piles of corpses are primarily from Buchenwald, which did not have a gas chamber or other execution facility. Instead, they are victims of disease and (towards the end of the war as Nazi supply chains crumbled) starvation. Of course the Nazis deserve much of the blame for their deaths (sort of the deal when you imprison someone) but there's a difference between deliberate genocide and typhus epidemic (which is what killed Anne Frank, among many others).