Other mistake: When Tut's henchman slowly reads that Bruce Wayne will donate his talking sphinx to the Black Museum at Scotland Yard from a newspaper, a close-up shows he is reading it upside down.
Other mistake: The opening scene and dialogue with Bruce and Dick responding to Gordon's call is from The Curse of Tut.
Answer: There wasn't one singular city used. It was shot in and around various locations in California, plus on a lot of sets and backlots. Ex. Some scenes were shot in LA, some in Pasadena, some in Santa Barbara, etc.
TedStixon