Pope Francis has called on the world's rich to help wipe out inequalities, in between visits to Rio de Janeiro's favelas and famous Copacabana beach.
The Vatican estimated that 1 million people turned out at Copacabana to greet the pontiff, who is in Brazil to celebrate World Youth Day.
According to Reuters, he was driven slowly through a huge crowd, stopping to kiss babies and even swapping his white skullcap with one hand-made by a follower who passed it to him through the car window.
Earlier, Francis visited a favela, or shanty town, in Rio de Janeiro.
In Manguinhos, a sprawling shanty town once ruled by drug lords and so violent, according to the Guardian, that it was known as "the Gaza Strip," the Pope told the crowd:
"No one can remain insensitive to the inequalities that persist in the world."
Francis, an Argentine known for frequent outings into the slums of Buenos Aires even as a cardinal, appeared to appreciate the close contact with the favela's residents.
That he chose to remind the world of inequality in Brazil seemed apt, given the huge number of Brazilians living in poverty. Despite a decade of economic growth in the country that has raised incomes for many, tens of millions of Brazilians still rely on little more than the basics to get by.
World Youth Day is promoted by the Vatican as a way to inspire young Catholics at a time when rival denominations, secularism and sexual and financial scandals continue to lead many to abandon the Church.