California governor Arnold Schwarzenegger and film director Steven Spielberg helped open the rebuilt backlot at Universal Studios on Thursday.
The £137 million construction, which features replicas of New York, London and Paris streets, replaces the outdoor sets destroyed by fire in 2008.
The four-acre site will feature on the studio tour, as well as be used in films.
Governor Schwarzenegger said the studio had helped make him a star in his former life as an actor.
"For me this is a kind of homecoming," he said.
"I have all kinds of really great, great memories of this studio."
Films shot on the lot prior to the blaze included classics such as Back To The Future, To Kill A Mockingbird and The Blues Brothers.