The effect: Leading his people out of Egypt, Moses causes the Red Sea to part in one of the most striking SFX scenes in history.
But how? Nowadays, CGI effects are so convincing, you could cause the Pacific Ocean to drain away at the touch of a button. But back in 1956, movie magicians had to use their initiative. In this sequence, they poured over 300,000 gallons of water into a vast tank, then played the film backwards and used some clever photography to give the impression of two giant walls of water.