With a stellar cast including Tom Hardy, Mark Rylance, Kenneth Branagh, Harry Styles, Cillian Murphy, Aneurin Barnard, and James D'Arcy, Dunkirk is set to be another Nolan masterpiece following acclaimed Interstellar, Inception, The Dark Knight.

Also read: Harry Styles is a star? Christopher Nolan didn't know that

While the movie is slated to be released on July 21, it has already garnered rave reviews from the critics worldwide. According to critics, Dunkirk is "chaotic, relentless, thrilling & one of the most captivating movies you will see this year. A master class in craft."

Dunkirk revolves around the 1940's infamous Operation Dynamo — the evacuation process from the French harbour of Dunkirk when thousands of soldiers from Britain, Belgium, Canada, and France were surrounded by Nazis.

Here are the five reasons why this movie is a must-watch for all.

Based on a true story

Director Nolan has given us some spectacular films to watch from Interstellar to Inception. But Dunkirk marks his first film based on a true story.

Christopher Nolan's Dunkirk movie
Christopher Nolan's Dunkirk movieYoutube screenshot

Less use of CGI

Cinephiles prefer authenticity more over CGI (computer generated image). Nolan tried to maintain the balance between the two in Dunkirk. The Interstellar director used real naval, a World War II plane and many more props to make this epic period drama more realistic.

Hans Zimmer's music

Ever since Batman Begins, legendary music director Hans Zimmer has become an inseparable part of every Nolan project. Zimmer's beautiful music sets the perfect pitch for the World War II action thriller.

IMAX 70 mm format

Nolan shot the movie with IMAX large format film cameras (70 mm) for an immersive viewing experience.

Christopher Nolan's Dunkirk movie
Christopher Nolan's Dunkirk movieYoutube screenshot

Harry Styles' debut movie

Every Harry Styles fan (better say One Direction fan) is eagerly waiting to see the debut work of their favourite singer. Recently Nolan admitted that he was not aware of Harry's stardom before casting him. "I cast Harry because he fit the part wonderfully and truly earned a seat at the table," Nolan said.