A chilling trove of Holocaust artifacts, including a windowless cattle car used by the Nazis to transport prisoners to their doom at Auschwitz, is set to go on display at a Manhattan museum — the first time many of the relics have been on US soil.

The collection — totaling more than 700 objects that also include concrete posts from the death camp, a dagger and helmet belonging to Holocaust architect Heinrich Himmler, and an SS gas mask — will be unveiled next month at the Museum of Jewish Heritage near Battery Park.

But it’s the restored boxcar that’s the largest and, to many, the most vivid portal into one of history’s darkest chapters.

“The dark, smelly car represents that moment of transition from the world of the living that people understood and trusted to the radically alien world of the camps where the doors opened and families were separated forever,” said leading Auschwitz expert Robert Jan van Pelt, who helped curate the collection.

Auschwitz survivor Ray Kaner, 92, looked on Sunday as a crane lowered the car onto a short segment of track outside the museum, and recalled that as she and her sister were forced in 1944 to board a similar train out of their home in a Polish ghetto, their Nazi captors promised a better home.

“We believed them, and we schlepped everything we could carry,” she said. “We still had great hope.”

The chairman of the museum’s board said that the exhibit, titled “Auschwitz. Not long ago. Not far away,” is intended not just as a history lesson but as a call to action against modern bigotry.

“The freight car is symbolic of the murder of millions of people,” said the chair, Bruce Ratner. “Auschwitz is not ancient history but living memory, warning us to be vigilant, haunting us with the admonition ‘Never Again.’

“It compels us to look around the world and mark the ongoing atrocities against vulnerable people and to take a firm stand against hate, bigotry, ethnic violence, religious intolerance and nationalist brutality of all kinds.”

The exhibit formally opens on May 8 — the 74th anniversary of Nazi Germany’s surrender and the camps’ liberation — and runs through Jan. 3.

With Post wires