Setting movies in ancient Rome is pretty commonplace in film history, but Gladiator re-defined the practice as a science (for multiple reasons). First, Ridley Scott's Oscar-winning epic recreated the famed Coliseum in grand fashion. Filmmakers took a small-scale version and, through the magic of the movies, made it into something that would easily rival what it must have looked like at the height of its glory.
However, recreating the venue was only half of the movie's CGI accomplishments, as producers were thrown a curveball when actor Oliver Reed sadly passed away before filming wrapped. So the film had to find a way to "virtually revive" Reed for his final shots. Special effects group The Mill used computer graphics to put Reed's face over the body of the double being used for the late actor. It's only about two minutes of footage, and most if takes place at night and using partially obscured shots, but it was a key scene that was needed to close out the character's story. The cost? A cool $3.2 million.