Superman Returns star Kate Bosworth wanted to enjoy being young and free. Fortunately, she just happened to be shooting a movie in the perfect place to do that: Sydney.

Following a mysterious absence of several years, the Man of Steel comes back to Earth in the epic action-adventure Superman Returns … While an old enemy plots to render him powerless once and for all, Superman (Brandon Routh) faces the heartbreaking realization that the woman he loves, Lois Lane (Kate Bosworth), has moved on with her life. Or has she?

Sorry, Superman, but Lois did move on with her life. But not with a rival superhero; she was having an affair with a city named Sydney.

It began with a 14-hour plane ride to a universe far away. The passenger: young actress Kate Bosworth, who had won the plum role of playing Lois Lane in Superman Returns, the eagerly anticipated latest installment in the Superman franchise. Bosworth knew that the movie was going to be filmed in Sydney, Australia, before she even landed­ the part, and, she says, the location was part of the allure. For Bosworth, who was born in Los Angeles, moved to Connecticut with her parents when she was nine and to Cohasset, Massachusetts, at 14, Sydney was as foreign as Krypton, Superman's birthplace - and that made it all the better. "I'd never been to Australia, and I don't think I'd ever been so far from home," she says, calling from her home base in L.A. "I went by myself, and it was a fantastic time for me."

Just like that, she was Down Under, "landing in a completely different world." A young woman named Jacqui showed Bosworth her hometown. "She greeted me when I came off the airplane, and she was working on the film as well," says Bosworth. "She is indicative of the Australian personality, just so friendly and sweet and down-to-earth."

Her mission? To facilitate Bosworth's on- and off-hours adventures. Which were what, exactly? I ask.

"Off-hours?" she asks, always the professional, Lois before Kate, the actress before the party girl.

"Yes, when you were off work?" I say.

"Um," she says, pondering. "Just to have a good time."

The consummate professional. This was an important quest.

"I mean, for me, it was a time in my life where I was really enjoying meeting new people and going out and having fun and really feeling young, feeling my age," she says. "I was 22 when I was there shooting this film, and there's a specific time in your life when you go away, whether it's to college" - she was accepted at Yale but deferred - "or abroad the first time. I've been to many places in my life, but this is the first time where I felt like I was very far away. I was very independent, so it was a time in my life where I was really discovering myself and enjoying being on my own."

You're only 22 once, Bosworth says, and she spent eight months of that magical year in the most magical city on earth.