Pope Francis has paid a sombre visit to the Nazi German death camp of Auschwitz-Birkenau.
He became the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than one million people, most of them Jews.
Wearing a white robe and skull cap, Francis walked slowly beneath the notorious gate at Auschwitz bearing the words "Arbeit Macht Frei".
He was then taken in a small car past barracks and brought to a spot in front of them, where he sat on a bench, his head bent in contemplation and prayer.
As an Argentine he is the first pope to visit who did not live through the brutality of World War Two on Europe's soil.
Both of his predecessors had a personal historical connection to the site, with the first, John Paul II, coming from Poland and himself a witness to the suffering inflicted on his nation during the German occupation.
His visit in 1979 made history and was part of the Vatican's historical efforts at reconciliation with Jews. Pope Benedict XVI, who visited in 2006, was a German who served in the Hitler Youth for a time as a teenager.
As a pope from overseas, Francis's visit helps to underline the universal importance of a site that in recent years has drawn ever more visitors from around the world.
Vatican and Polish church officials said he would express his sorrow in silence at the site, mourning the victims in quiet prayer and meditation.
Francis had been scheduled to fly from Krakow to Oswiecim, the small town where the former death camp is located, but due to bad weather travelled the 40 miles by car instead.
It is his third day of a five-day visit to Poland that includes meetings with young pilgrims taking part in World Youth Day, a global youth celebration.
Friday is devoted to the theme of suffering and later in the day Francis will visit a children's hospital in Krakow.
Pope Francis met several survivors of the death camp during his visit.
One by one, he stopped, shook their hands and bent over to kiss the elderly survivors on both cheeks. One woman kissed his hand and he exchanged a few words with them.
He then carried a large white candle and placed it at the Death Wall, where prisoners were executed.
Pope Francis also prayed in the dark underground prison cell of a Catholic saint, Maximilian Kolbe, a Polish friar who sacrificed his own life during the war to save the life of another man.
A few shafts of light from a tiny window were the only light cast on the white figure of Francis, who knelt for many minutes as he prayed before he crossed himself and rose to his feet.