Beneath the indignation of Holocaust denialism and an idiotic agenda being pushed, the general response among historians of the Holocaust to this larger question is something to the effect of "so what?" The death camps have not been kept in situ an it is not as if they have been preserved in amber for future generations. These were built structures that have a relationship to human beings; this did not stop after 1944/45. The camps themselves were largely temporary structures and not meant to last. Auschwitz, which in many respects was an atypical camp and had semi-permanent structures (mainly in Auschwitz-I), has been struggling in recent years with balancing the need to preserve the camp and its relics and still keeping it open to visitors. Furthermore, the camps themselves were not preserved by the Third Reich, which willfully destroyed much of the evidence of judeocide. Denialists love to point out that Auschwitz's gas chambers are a reconstruction -ergo fake- but this is no big state secret. Camp guide materials point this out and historians know this as well.

The more interesting angle to this is the interlinked questions of how and why these sites were preserved. The postwar Polish government, for example, sought to make Auschwitz a memorial of Polish suffering. Part of this instrumentalization involved an embellishment of the numbers of humans killed there, as well as sidelining non-Polish victims and Polish Jews in commemorations. This was of a piece with other commemorative and preservation practices within the Eastern bloc. A high body count proved fascist barbarity and the martyrdom of its victims. Like the Auschwitz gas chamber reconstructions, this is not a secret to historians. Historical accuracy often falls to the wayside with such a politicized environment, but this does not mean reconstructions were cut from new cloth either. The documentation, survivors' and perpetrators' accounts pretty much confirm that structures existed that were used for mass gassing. Additionally, the overall process of finding the right killing method was complicated and evolved after a period of trial and error. Experiments with the Zyklon-B pesticide as a killing agent took place concurrently with the use of carbon monoxide gas. The camps' extermination process was in a constant state of flux.

This poses a question for commemoration and reconstruction, because the issue of which period in the camps' history should be preserved is a thorny one. None of Auschwitz's purpose-built gas chambers ( this site has a good overview ) survived the war, but the Auschwitz State Museum's reconstructed one using surviving components and materials from the demolished chambers. The reconstructed chamber area in Crematoria I reflected an earlier part of the camp's history when that area was used for mass exterminations. Later, it became a storage area as other parts of the camp became more prominent in mass killing operations. Crematoria I serves as a placeholder of physical memory for all of these other sites; people were murdered at Crematoria I, but not all of Auschwitz's victims died there.

Denialists love to bring up the issue that the preservation of Holocaust sites represents something artificial, but much the same could be said of any heritage site. Preserving these areas is a complicated affair balancing very complicated rationales for preservation as well as making sure the public can experience these sites without damaging them. Not surprisingly, historical preservation is not a static process and methods of preservation acceptable for some generations can soon become outdated.