Curiosidades

Following a preview of the film, a questionnaire was distributed among the viewers asking what scene they liked. One person answered, "The scene where Robert Taylor saved Deborah Kerr from the fire." This was in reference to the fact that much of the stock footage used in the film came from Quo Vadis (1951).

Although the prior year's A Máquina do Tempo (1960) was a big hit for George Pal, MGM gave him a tiny budget for this picture, hence the many shortcuts and footage used from other films. Russell Garcia, who scored the film, recycled themes from "The Time Machine"--even going as far as re-using entire cues from the earlier film. Additionally, William Tuttle, the makeup artist, had a considerable amount of blue body paint left over from "The Time Machine": it may be noted that Neptune (who appears to Demetrios in a hallucination) is the same shade of blue as the Morlocks.

The special effects model of the Atlantean submarine has been part of the collection owned by Forrest J. Ackerman for many years.

George Pal was unhappy with the script but was forced to begin production before it had been polished due to an impending writers' strike. The strike occurred during production, which stopped any rewrites.

In addition to his credited narration, Paul Frees, without additional credit, dubbed the voices of three actors: an unknown appearing briefly as a messenger, and both Wolfe Barzell and Edgar Stehli, who played the fathers of the hero and heroine respectively.