Around 2,000 Swiss Catholics aged 16 to 30 are in the German city of Cologne to take part in World Youth Day celebrations, which run until Sunday.
The week-long event will be marked by the attendance of Pope Benedict XVI, who is visiting his homeland on his first trip outside the Vatican since his election in April. In total 400,000 young people are expected.
The event culminates in an open-air Mass on Sunday preceded by a vigil in the presence of the Pope on Saturday night.
Marco Schmid from the Swiss Bishops' Conference said 1,000 participants were expected from German-speaking Switzerland, 600 from the French part, and 400 from the rest of the country.
"For us it was really a surprise to see how many people were interested," said the Swiss media coordinator for the World Youth Day.
Schmid told swissinfo he believed last year's Catholic youth gathering in Bern – attended by Pope John Paul II and 14,000 young people - had stirred up interest in the Cologne event.
"I think it's a consequence of this event in Bern that a lot of young people heard of this World Youth Day and this is probably now the fruit of that," he said.
Prayer and meditation
The German branch of the Catholic reform movement We Are Church has expressed scepticism about the international youth meeting, saying that it risks being exclusively a pope-centred event.
It warns that the Pope's presence could overshadow the real purpose of the meeting: to enable young people from different countries to discuss matters of faith.
But Schmid rejects the criticism, saying the spiritual dimension of the meeting is very important and the focus will be on worship.
"Of course the Pope is important for this meeting, but I'm sure that isn't the essential point for the young people. I think first of all they want to meet other young people and share their faith," he commented.
"I think it will be more spiritual than last year in Bern. There will be more prayer and meditation."
Schmid added that the Church leadership was interested in what young people had to say, and there would be opportunities to speak with the bishops every morning after the religious teaching.
"There will be about 700 bishops there, and I think they will listen to the young people –their problems, wishes and dreams," said Schmid.
"It's a good opportunity for dialogue."
swissinfo, Morven McLean
The 20th World Youth Day – Cologne 2005 runs from August 15-21.
World Youth Day was launched in 1986. An international event to mark it takes place every two to three years in a different city.
The last international gathering was in Toronto in 2002.
This year's theme is "We have come to worship him", and is taken from St Matthew's Gospel.