KRAKOW, Poland (AP) — Elon Musk visited the site of the Auschwitz-Birkenau World War II Nazi German death camp on Monday, after the billionaire faced criticism for subscribing to an antisemitic conspiracy theory and allowing hate messages on his social media platform, X, formerly known as Twitter.

The private visit was apparently in response to calls from some Jewish religious leaders for Musk to see with his own eyes the most symbolic site of the horrors of the Holocaust.

Musk was photographed visiting the Birkenau site. Birkenau is an area near Oswiecim, in southern Poland, fenced off with barbed wire, where wooden barracks that were simple shelters for the inmates and the ruins of a gas chamber can be found and where a monument to the victims stands. International ceremonies are held there each year.

Musk had been expected to make the visit on Tuesday, together with political figures attending a conference of the European Jewish Association on the rise of antisemitism.

Later Monday, Musk was to discuss antisemitism online as part of a conference by the European Jewish Association held in Krakow ahead of the Jan. 27 International Holocaust Remembrance Day, which takes place on the anniversary of the camp’s 1945 liberation.

Musk sparked outcry in November with his own tweets responding to a user who accused Jews of hating white people and professing indifference to antisemitism. “You have said the actual truth,” Musk tweeted in a reply.

After advertisers starting pulling out of X, Musk said the post was the “dumbest” he had ever written.