Jake Gyllenhaal and Joaquín Phoenix in western filmed in Aragón

French director Jacques Audiard will be leading up the confusingly-titled Les Frères Sisters, based upon the novel of the same title by Patrick de Witt and also starring John C Reilly and Riz Ahmed.

It tells the story of two brothers travelling across the west coast of the USA during gold-rush fever, charged with carrying out a contract killing.

The novel and film are said to be more a psychological study of two brothers who are very different in personality rather than a murder story.

As yet, the exact locations in Aragón have not been revealed, but an audition on Tuesday this week (April 25) in Jaca, in the Pyrénéen province of Huesca, is due to take place seeking extras and actors of various ages and both sexes to play minor roles.

According to the Aragón Film Commission, men and women aged at least 18, and children aged six to 12 are sought.

Les Frères Sisters was originally due to be shot in Canada, but the land-locked region of Aragón – which stretches from the French border to about a third of the way down the mainland and is slightly east of the centre – was chosen instead.

One of Spain's most stunningly-beautiful regions, every turn in the road brings completely different scenery, from densely-forested and snowy mountains which appear Alpine or even Scandinavian through to dramatic red rock formations that resemble the Grand Canyon, rocky rivers, emerald-green meadows, lakes, and abandoned villages.

The northern and southern provinces of Huesca and Teruel respectively are home to some of Spain's most popular ski slopes and elaborate Mudéjar – or late Moorish – architecture, and Teruel is well-known for its spectacular cathedral and the statues of the famous 'lovers' of the Romeo and Juliet-style legend.

The middle province of Zaragoza is home to the city of the same name which house the Expo a decade ago and is Spain's fifth-largest metropolitan area after Madrid, Barcelona, Valencia and Sevilla, in that order.

The photograph shows the part-Danish actor Jake Gyllenhaal, one of the better-known cast members of Les Frères Sisters.