Eva Kor survived the sadistic pseudoscientific medical experiments carried out on twins at the Auschwitz death camp. She dedicated herself decades later to telling of the Holocaust horrors spawned by religious and racial hatred, while preaching the power of forgiveness as a means of healing from devastating trauma.

Ms. Kor took young people on annual summer tours of Auschwitz. While conducting a tour, she died on Thursday at 85 at a hotel in Krakow, Poland, near the site of the former death camp. It was there that she and her twin, Miriam, had been among some 1,500 sets of twins who were victims of experiments, including the injections of germs, overseen by the German doctor Josef Mengele.

Her death was announced by the Candles Holocaust Museum and Education Center (for Children of Auschwitz — Nazi Deadly Lab Experiments), which she had opened in 1995 in Terre Haute, Ind. She had settled there in 1960 with her husband, Michael Kor, a fellow Holocaust survivor.

Ms. Kor and her sister created a nonprofit organization, named Candles, in 1984, after locating more than 100 other twins who had been tortured by Mengele, hoping they would connect with each other so many years later.