He was greeted by hundreds of schoolchildren, whose excitement was undiminished by the mist and rain, before heading to the Marian shrine, the site of an apparition of the Virgin Mary in 1879.
"He has a hard job to do to try and bring around a lot of changes in the Church but he is doing his best I feel", said Eileen Grier-Gavin, who came from County Mayo in western Ireland to see the pope pass by.
The pope will travel on Sunday to Knock, a small western village steeped in Catholicism that welcomes 1.5 million pilgrims a year, before finishing his trip by saying mass in Dublin's Phoenix Park, where a large cross erected for the 1979 visit still dominates the skyline.
It's a very different reception - and a very different Ireland - to the last papal visit in 1979, when Pope John Paul II was greeted like a rock star in Phoenix Park by almost one-third of the country's population.
Protests are also planned.
The Emeritus Pope's 2010 text, sent to the Irish church following revelations of widespread cover-ups of child sexual abuse, was viewed as failing to face up to responsibility for the scandal.
"With regard to the most vulnerable, I can not fail to acknowledge the grave scandal caused in Ireland by the abuse of young people by members of the church charged with responsibility for their protection and education", he said.
"There can only be zero tolerance for those who abuse innocent children or who facilitate that abuse", said Varadkar.
Survivors handed a letter to the pope, in English and in Spanish, telling him that 100,000 mothers were forcibly separated from their babies in Ireland, and were told it was a "mortal sin" to try to contact their children.
"We must now ensure that from words flow actions".
Michael D Higgins also told Pope Francis of the anger felt by those in Ireland who were abused as children by Catholic clerics.
He restated previous acknowledgement of the "grave scandal" of abuse.
Francis' trip to Ireland, the first by a pope in 39 years, has been overshadowed by renewed outrage over the Catholic Church's systemic failures to protect children, following revelations of sexual misconduct and cover-up in the US church hierarchy, a growing crisis in Chile and the prosecutions of top clerics in Australia and France. "There are one or two objectors, but I think they should keep their objections to themselves and get into the spirit of the thing", said Christina O'Riordan, a 76-year-old retired teacher. "Building on our intertwined history & learning from shared mistakes, it can be one in which religion is no longer at the centre of our society, but in which it still has an important place".
The taoiseach said that the Republic of Ireland had modernised its laws, "understanding that marriages do not always work, that women should make their own decisions and that families come in many forms" - including those headed by a lone parent, same-sex parents or parents who are divorced and remarried.
Burke said the victim "preferred to remain anonymous".
A damning report last week into abuse in the US state of Pennsylvania, combined with scandals in Australia and Chile, have formed what one Vatican official called "a ideal storm" and already overshadowed a trip where the main objective is to close a week-long worldwide Catholic gathering.
Supporters wait to see Pope Francis outside Our Lady of Lourdes Church, Dublin. He said the pope did not respond, and McCarrick continued in his role as a public emissary for the church.
However, he will also fulfil a number of other engagements. "Corruption has reached the very top of the church's hierarchy", he wrote.