The young stars of the upcoming Christopher Nolan film Dunkirk – Harry Styles, Fionn Whitehead, Tom Glynn Carney and Jack Lowden – recently sat down to a roundtable interview to discuss their experiences on the set of the World War II epic and what audiences should expect when it arrives in theaters later this month.

RELATED: Harry Styles Stops Concert To Honour Manchester Concert Bombing Victims

“It’s going to be a super intense movie,” says Styles, who takes on his first acting role in the survival flick. Based on an original screenplay by Nolan, the movie tells the story of the Dunkirk evacuation in 1940, where hundreds of thousands of British and Allied troops were trapped on Dunkirk beach with enemy forces closing in around them.

Shot on location in France, on IMAX 65 mm, the film used a large amount of practical effects, including planes from the era and ships which had genuinely participated in the real life event. Up and coming actor, Whitehead, discusses the atmosphere on set in the above interview.

“I was coming out onto the beach and there was 1300 extras all dressed in battle gear, spitfires flying overhead, destroyer’s in the background, the beach was set dressed, sandbags and trucks and everything, and there was explosions going off in the sand – it was just so real.”

RELATED: Intense New Trailer For Christopher Nolan’s Star-Studded War Epic ‘Dunkirk’ Arrives

Dunkirk boasts a star-studded cast, including former Nolan collaborators Tom Hardy (The Revenant, Inception) and Cillian Murphy (Inception, The Dark Knight), plus Kenneth Branagh (My Week With Marilyn, Hamlet) and Mark Rylance (Bridge of Spies, Wolf Hall). But in his introduction to the roundtable featurette, the director reveals that he also wanted to cast fresh faces, “We wanted to cast people of the right age; we wanted kids who would experience these events the way people would have at the time.”

While any Christopher Nolan movie is sure to draw hype, a lot of the conversation regarding Dunkirk has revolved around One Direction member Harry Styles. In a recent interview with Digital Spy, Whitehead said the hysteria surrounding Styles and his involvement in the film “has got a bit silly”. The twenty-year-old rising star told the publication, “I think the focus should not be Harry Styles doing a movie, it should be on the piece in general or his ability to act. And he’s great.”

Dunkirk opens in theaters on July 21, 2017.