Flight of the Lost Balloon is a 1961 film produced, written and directed by Nathan Juran that was filmed in Puerto Rico. It stars Mala Powers and Marshall Thompson with the working title being Cleopatra and the Cyclops. The film was inspired by Jules Verne's Five Weeks in a Balloon and beat the major Irwin Allen film release of the book to the cinemas. However the name of Jules Verne was dropped and was nowhere to be found in the credits, though the name of Verne's balloon, the Victoria remained. As a promotional gimmick people who bought tickets for the film were given a "motion sickness pill".