Its official: The Vatican has announced that Pope Benedict XVI will visit the city of Cologne on the occasion of World Youth Day this August. The pontiff will stay from Aug. 18 to 21 in the city on the Rhine, his first trip to Germany since becoming pope. The highlight of the trip will be a mass on Sunday, August 21, on the Marienfeld near the surburb of Frechen. Organizers are expecting 800,000 visitors. Benedict's predecessor, John Paul II, had originally planned to make the trip. He visited Germany three times during his tenure as head of the Catholic Church.