20,000 Leagues Under the Sea (1916)

Fun silent-era epic. The images of the ships at (or under) sea, the balloon careening towards the island, the fist fights, and the explosions are all among the best of their time. The extensive underwater shots are still exciting 100 years later, even though they eventually turn redundant. The characters, as in most silent films, are sketchy, but the white-bearded Captain Nemo has an undeniable presence and dignity. The story is remarkably complex for a pre-1920s film. It is generally considered the first feature-length science fiction film, though the Danish "Verdens Undergang" (c. 77 min, with special effects disaster footage) was released the same year.

Goldweber, David Elroy (2012-06-14). Claws & Saucers: Science Fiction, Horror, and Fantasy Film: A Complete Guide: 1902-1982 (Kindle Locations 72486-72494). David E. Goldweber. Kindle Edition.