To visit Auschwitz is to find an unfathomable but strangely familiar place. After so many photographs and movies, books and personal testimonies, it is tempting to think of it as a movie-set death camp, the product of a gruesome cinematic imagination, and not the real thing.

Alas, it is the real thing.

That is why, since its creation in 2009, the foundation that raises money to maintain the site of Auschwitz-Birkenau has had a guiding philosophy: “To preserve authenticity.” The idea is to keep the place intact, exactly as it was when the Nazis retreated before the Soviet Army arrived in January 1945 to liberate the camp, an event that resonates on Holocaust Remembrance Day, on Thursday.

It is a moral stance with specific curatorial challenges. It means restoring the crumbling brick barracks where Jews and some others were interned without rebuilding those barracks, lest they take on the appearance of a historical replica. It means reinforcing the moss-covered pile of rubble that is the gas chamber at Birkenau, the extermination camp a few miles away, a structure that the Nazis blew up in their retreat. It means protecting that rubble from water seeping in from the adjacent ponds where the ashes of the dead were dumped.