The Lost City of Z is a voyage of discovery in the jungles of Colombia

Director James Gray and star Charlie Hunnam tell us about their experiences in the jungles of Colombia during the filming of The Lost City of Z.

The Lost City of Z is based on the life of explorer Percy Fawcett, who set out at the dawn of the 20th century to locate a rumoured lost city in the heart of the Amazon forests. Photo by Aidan MonaghaShow more

At the heart of James Gray's acclaimed film The Lost City of Z is the story of real-life British explorer Percy Fawcett.

A legendary figure who ventured into the uncharted depths of the Amazon jungle on several occasions in the early 1900s, his adventures inspired Sir Arthur Conan Doyle's fictional story, The Lost World.

In short, you might think of Fawcett as the Indiana Jones of his day.

"He's a pretty remarkable guy," says actor Charlie Hunnam (Sons of Anarchy), who plays his role in the film. "He's such a complex character."

Fawcett was obsessed with finding “Z”, a rumoured lost city deep in the Amazon, which no outsider had ever seen. In pursuit of this, he spent years away from his wife, Nina (Sienna Miller), and their two young sons.

“I think Fawcett was one of those rare individuals who had the courage, discipline and selfishness to put his internal responsibility to the forefront,” says Hunnam.

Gray, the esteemed director of Two Lovers and The Immigrant, was determined to recreate Fawcett's journey as accurately as possible. This led him to cast indigenous actors.

“I thought what would make this a different take on ‘the white man in the jungle’ is that it’s hitting the issue directly head on,” he says.

"That's what the movie's about. We don't have Alec Guinness playing an Arab. As much as I love that movie [Lawrence of Arabia, in which Guinness stars as the Mecca-born Prince Faisal], it's a ridiculous piece of casting."

In pursuit of realism, the film also took the cast and crew to film in the jungles of Colombia.

“I didn’t find it a shock to the system,” says 37-year-old Hunnam, “but it definitely was not without its challenges…you can never relax when you’re in that environment. “It’s not like being in a forest in Europe where it’s pretty benign in terms of the things that can really harm you. It’s just a multitude of things all over the place that are pretty deadly – from plants to insects to larger animals.”

If the actor wasn’t “particularly bothered” by such trials, Gray “was profoundly ill-at-ease”, says Hunnam, who describes the director as “a magnet to every deadly creature in a 10-mile radius”.

He cites one particular incident in which Gray was sitting behind a camera monitor in a small tent and leaning his back against a spider on the other side of the gossamer-thin canvas.

“One of the local guys saw this, panicked, ran over and hit it off,” says Hunnam.

“If that spider had bitten him, he would have been dead in 30 seconds.”

Physical fears aside, Gray was determined to make something original.

“I wanted to try to reach for something that was much more poetic in nature,” he says.

This meant avoiding ground covered by classic jungle-adventure films such as Werner Herzog's Aguirre, the Wrath of God and Fitzcarraldo.

“Obviously I love those movies, they’re great. They’re hugely inspiring,” says Gray. “But I didn’t want to rip them off.”

The only film he did watch before filming began was Burden of Dreams, a documentary about the tumultuous making of Fitzcarraldo – if only to learn what not to do. The Lost City of Z was not entirely shot on location in Colombia. Scenes of Fawcett lecturing at the Royal Geographical Society were filmed in Belfast.

Miller, who filmed High-Rise (directed by Ben Wheatley, whose latest film Free Fire is in cinemas from tomorrow) in the same city the previous summer, shot all her scenes here, calling the shoot an "isolating experience" due to the nature of her character.

“She was quite lonely,” she says. “I think that was something I understood in her when I read it.” Rather than staying back with the rest of the crew in Belfast, the actress relocated to nearby Bangor, “so it felt melancholic”.

Hunnam went to even greater extremes to get himself into character; he cut himself off from his girlfriend of 11 years – the jewellery designer Morgana McNelis. “I wanted to exacerbate this sense of sacrifice and isolation that is created sometimes by travelling so much,” he says.

He didn’t use the internet, send emails or make a phone call for the four months of shooting.

“It’s amazing how stable life becomes when you’re not being stimulated one way or another…when you’re just living in the present,” he explains.

After his return to civilisation, Hunnam was delighted with the end result of the efforts by the cast and crew. The first time he saw the film, he took McNelis.

“She watched it and really received it in the way that I hoped she would,” he says. “Both for James and myself, it was really present in our minds as we were making this film – really we were making it for our loved ones.”

• The Lost City of Z is in cinemas from April 27