Based on the success of "The Man with No Name trilogy", Leone was invited to the United States in 1967 to direct "Once Upon a Time in the West" ("C'era una volta il West") for Paramount Pictures. The film was shot mostly in Almería, Spain and Cinecittà in Rome. It was also briefly shot in Monument Valley, Utah. The film starred Charles Bronson, Henry Fonda, Jason Robards and Claudia Cardinale. "Once Upon a Time in the West" emerged as a long, violent, dreamlike meditation upon the mythology of the American Old West, with many stylistic references to iconic western films. Audience tension is maintained throughout this nearly three-hour film by concealing both the hero's identity and his unpredictable motivation until the final predictable shootout scene. Perhaps unsurpassed as a retribution drama, the film's script was written by Leone and his longtime friend and collaborator Sergio Donati, from a story by Bernardo Bertolucci and Dario Argento, both of whom went on to have significant careers as directors. Before its release, however, it was ruthlessly edited by Paramount, which perhaps contributed to its low box-office results in the United States. Nevertheless, it was a huge hit in Europe, grossing nearly three times its $5 million budget among French audiences, and highly praised amongst North American film students. It has come to be regarded by many as Leone's best film.