OSWIECIM, Poland — Catholic pilgrims have begun gathering in southern Poland ahead of the midweek arrival of Pope Francis for World Youth Day, a days-long meeting of young people.

Young people convened for prayers in Krakow on Monday, while thousands also visited the former Nazi death camp of Auschwitz-Birkenau.

On Friday, Francis will become the third pontiff to visit the somber memorial site, following in the footsteps of John Paul II and Benedict XVI.

Fatima Sonndevile, a pilgrim from Spain, said: “There is always light, and I think we have to find it. I think that is the reason pope sent us to (see) this ... to see what humanity did in the past, and try (to) not do it again.”

Though the Catholic youth have to wait two more days for the pope, the pontiff had a message for them already Monday.

“Dear young people, we offer to the world a mosaic of so many races, cultures and peoples united in the name of Jesus,” Francis said in a tweet with the hashtag #Krakow2016.