Doctor Zhivago (1965) was the latest in a string of
David Lean films set in harsh locations. Where the story is actually based, the Soviet Union, would be an impossible filming location. Not only did the government of the Soviet Union not allow filming there, but they wanted to talk Lean out of making the movie at all as the novel on which the film is based was banned there. Lean instead decided to film the movie in the Spanish plains, which would double for Siberia and where sets would be built to film the city sequences.
—Huggo