Doctor Zhivago (1965)

Continuity mistake: The city railroad scenes were filmed in Spain, and many of the forest railroad scenes were filmed in Finland; in both of those countries, most of the railroad track is broad gauge (the rails are more than 5 feet apart). The plains and mountains railroad scenes were largely shot in Canada, where the rails are "standard gauge": 4' 8 & 1/2" apart. The rails can be seen to jump between far apart and closer together more than once as the movie progresses.

Gen. Yevgraf Zhivago: A nameless number on a list that was lost, or mislaid. That was common in those days.

Trivia: Geraldine Chaplin, the actress who plays Dr. Zhivago's wife, is the daughter of the silent film actor, Charlie Chaplin. Her maternal grandfather was famed playwright Eugene O'Neill.