There were two reports from the Polish underground that described what was going on at Belzec. The Wikipedia article you cite links to a description of the cam

There were two reports from the Polish underground that described what was going on at Belzec. The Wikipedia article you cite links to a description of the camp which references those reports. The Wikipedia article you cite also references 7 survivors of the camp, not two. It's also not true that "even simple facts like location of buildings.." are not known. There have been several archeological examinations of Belzec. http://www.holocaustresearchproject.org/ar/modern/archreview.html http://www.holocaustresearchproject.org/ar/modern/archreview... https://www.researchgate.net/publication/250397297_Excavating_Nazi_Extermination_Centres https://www.researchgate.net/publication/250397297_Excavatin... The intent of your post would seem to be to be of a denialist nature.