Second Gentleman Doug Emhoff visited the Auschwitz-Birkenau Memorial and Museum in Poland Friday, marking Holocaust Remembrance Day and the 78th anniversary of the death camp’s liberation.

In an emotional visit, Emhoff laid a wreath at Auschwitz and placed a white stone, a Jewish tradition, at the remnants of a crematorium in Birkenau. After walking under the notorious “Arbeit Macht Frei” (Work Sets You Free) gate, Emhoff wrote a long message in the museum’s guestbook.