Trivia: Barneby talks to Cornelius (Michael Crawford) about going to Barnum's museum. Michael Crawford played Barnum in a stage play in the 90's.
Trivia: Originally, Metro Goldwyn Mayer had planned for producer Roger Corman to make a film entitled "Captain Nemo and the Floating City," but the project collapsed early on. Producer Steven Pallos later resurrected the project as "Captain Nemo and the Underwater City," and this time the film was completed.
Trivia: When Walt Disney died of lung cancer in the mid-1960s, his last written words were "Kurt Russel," alluding to a Disney actor who was only a young teenager at the time. Kurt Russel went on to become a prominent actor in film in his adult years.