Goofs:
Continuity: When Jason is being held in the Hydra's tail, he strikes the tail with his sword, but the sword bounces off the tail as if the tail is made of rubber. (more)

Trivia:
This British / American film was filmed and released in the waning years of the Italian-produced sword-and-sandal / mythological muscleman movies. Many of those productions dealt with Jason. Most unusual for the time was the casting of British actor Nigel Green as Hercules. Although he was very tall, he lacked the bodybuilder physique that moviegoers were used to seeing for this character. Although film was not able to match the scale of spectacle of the European productions, the elaborate special effects by Ray Harryhausen gave it the look of a more expensive production, contributing to its box-office success. (more)

Filming Locations:
Capaccio, Salerno, Campania, Italy (more)

Quotes:
Zeus: If I had to punish *every* blasphemy, I would have *no followers*! (more)