Singer Katy Perry visited the Auschwitz-Birkinau State Museum in Poland and came out with a `heavy` heart.

The 30-year-old took the time following her show in Krakow, Poland to visit the site of notorious concentration camps Auschwitz I and Auschwitz II-Birkenau Wednesday, where more several people were murdered during the Holocaust, reports femalefirst.co.uk.

`My heart was heavy today," Perry captioned a photograph she took on the grounds.

She also wrote the text from the main memorial plaque at the site: `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.`

Perry had previously been in Milan, Italy, and then Prague -- where she was spotted taking in the sights in track pants and a cozy puffy coat -- before travelling to Poland.