To end "Catholic Woodstock" -- as World Youth Day has been called by the Portuguese press -- Pope Francis told 1.5 million weary-eyed and sleep-deprived young people in Lisbon not to let their "great dreams" of changing the world be "stopped by fear."

In his homily for the closing Mass of World Youth Day Aug. 6, the pope asked for "a bit of silence" from the pilgrims who, after staying overnight in Lisbon's Tejo Park following the previous night's vigil, at 6 a.m. were already dancing to techno music mixed by a DJ priest before the pope's arrival.

"Let's all repeat this phrase in our hearts: 'Don't be afraid,'" he told the hushed crowd. "Jesus knows the hearts of each one of you, the successes and the failures, he knows your hearts," Pope Francis said. "And today he tells you, here in Lisbon for this World Youth Day: 'Don't be afraid.'"

As dawn broke over the riverside park, pilgrims emerged from tents, tarps and sleeping bags to prepare for Mass. Violeta Marovic, 19, from Chicago, told Catholic News Service that the pilgrims spent the 10 hours between the previous night's vigil and the papal Mass "sleeping very little," dancing, playing games and exchanging gifts with other young people from around the world; she was wearing bracelets given to her by pilgrims from Italy and Poland.

A theology major at the University of Dallas, Marovic said she normally gets "nervous" when she tells people what she studies, but she has been comforted by seeing the huge amount of people so passionate about their faith, noting that young Catholics often "feel alone" when practicing their religion in the United States.

At the front of the crowd, which extended across both banks of Lisbon's Trancão River, 30 cardinals, 700 bishops and 10,000 priests concelebrated the Mass with Pope Francis. Portuguese President Marcelo Rebelo de Sousa was seated in the front row.

Cardinal Manuel do Nascimento Clemente of Lisbon thanked the pope for making World Youth Day an opportunity for young people to come together and build a better tomorrow "after a pandemic that has confined them and otherwise distanced them from each other and from the best (version) of themselves."

Cardinal Kevin Farrell, prefect of the Dicastery for Laity, the Family and Life, which organizes World Youth Day, thanked Pope Francis for bringing together in Lisbon young people "who have been pilgrims of peace in times in which many, too many, wars are being fought in so many parts of the world."

Before revealing the location of the next World Youth Day, Pope Francis invited young people to travel to Rome for a youth celebration during the Holy Year 2025. The next World Youth Day, to take place in 2027, he continued, "will be in South Korea, in Seoul," he said to cheers from the sizeable groups of Koreans scattered in the crowd.

In remarks after Mass, the pope also recalled the suffering of Ukraine and asked young people if he, "an old man," could share a dream of his: "the dream of peace, the dream that young people may pray for peace, live in peace and build a peaceful future."

Using the Portuguese word for thank you -- "obrigado" -- the pope thanked the organizers of World Youth Day, the volunteers who made it possible and the city of Lisbon, which he prayed would "remain in the memory of these young people as a house of fraternity and a city of dreams."

"And 'obrigado' to all of you, dear young people," he said before praying the Angelus. "God sees all the good you are, and only he knows what he has planted in your heart. Go from here with what God put in your heart."

The crowd dispersed after Mass, streaming through the streets of Lisbon, filling closed-down highways while waving the flags of the world.