Entrance gates to the former Auschwitz concentration camp. (JANEK SKARZYNSKI/AFP/Getty Images)

Pop star Katy Perry, in Europe for her ‘Prismatic World Tour,’ visited Auschwitz yesterday after her concert in Krakow. She posted an Instagram photo from the former concentration camp, with an emotional message for her 15 million followers.

My heart was heavy today. For ever let this place be a cry of despair and a warning to humanity, where the Nazi murdered about one and a half million men, women and children mainly Jews from various countries of Europe. Auschwitz – Birkenau 1940-1945 "The one that does not remember history is bound to live through it again" George Santayana

A photo posted by KATY PERRY (@katyperry) on

The singer, who earlier this month performed at the Super Bowl alongside dancing sharks, is usually known for her upbeat, bubblegum persona. But it’s not the first time she’s shown an emotional depth not typical of most megastars. When 16-year-old Olivia Wise, a Canadian teen with brain cancer, recorded a cover of Perry’s hit “Roar” that went viral, Perry responded with a video message of her own for Wise. (Wise died the following month.)

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