French pilgrims rest in their appartment window in Krakow on July 30, 2016, during a visit of Pope Francis at the World Youth Day (WYD). / AFP / JOE KLAMAR

Pope Francis walks with youth representatives after passing the «Door of Mercy» at Campus Misericordiae on July 30, 2016 in Brzegi as part of the World Youth Days (WYD). Pope Francis is in Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / FILIPPO MONTEFORTE

Youth representatives and Pope Francis drive with the popemobile at Campus Misericordiae on July 30, 2016 in Brzegi as part of the World Youth Days (WYD). Pope Francis is in Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / FILIPPO MONTEFORTE

Pope Francis and young representatives of every continent pass the Door of Mercy on July 30, 2016 on the Campus Misericordiae in Brzegi, Poland, ahead of a prayer Vigil, as part of the World Youth Days (WYD). Pope Francis is in Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / WOJTEK RADWANSKI

Pope Francis and young representatives of every continent pass the Door of Mercy on July 30, 2016 on the Campus Misericordiae in Brzegi, Poland, ahead of a prayer Vigil, as part of the World Youth Days (WYD). Pope Francis is in Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / AFP PHOTO / WOJTEK RADWANSKI