Charlie Hunnam plays Fawcett, and says that he related to the man's selfish obsession, abandoning his family for his quest. "It was an extraordinary script," Hunnam says. "It struck me as the best opportunity I'd ever been given, because of the breadth of the story and substance of the story, but also the complexity of this character. There were just certain elements of Fawcett that I had been becoming more and more interested in exploring just in my regular life."

Charlie Hunnam in The Lost City Of ZCharlie Hunnam in The Lost City Of Z

The film was shot over five months in Colombia, and Hunnam initially tried to keep in touch with his girlfriend Morgana McNelis. But the remote location made this impossible, as there wasn't reliable phone or internet. So he decided to write to her a letter a day. But even that proved tricky. "I received a letter from her," he says, "and I realised that from the tone of it and things she was saying that she hadn't received the two letters that I sent before!"

Hunnam says that this actually helped him understand Fawcett's "loneliness and isolation" as he pursued his passion. "One of the things we wanted to explore in the film was the conflict between family life and the exterior demands that are made on us," he says. "I've become very aware of that conflict in my own life, pursuing my career and my own sense of personal obsession, and how much sacrifice that requires of my personal life and how much I've come to neglect my personal life and the people in it."

He particularly loved that director James Gray approached the film from a more personal perspective. "The current environment of filmmaking is very spectacle based," Hunnam says. "So just the idea that we would go back to a classic idea of character and explore the environment as it is. It's the way films should be made."

And he thinks Fawcett's story goes beyond that. "It's relevant to anybody living in the world where they have a sense of being oppressed," he says, "and this horrible tendency we have of prioritising one person's need over another, whether that's based on economic standing or race or creed or sexuality or gender."

Watch the trailer for The Lost City Of Z: