The Joker's Flying Saucer - S3-E24
Character mistake: Vertigris tells Joker he planted a bomb in the Batmobile while it was parked in front of City Hall/Police HQ. Only in this instance, it wasn't. It was parked in the alley out back, the better to hide his bomb-planting from public view, so it's strange that he'd forget this. (00:08:15)
Louie's Lethal Lilac Time - S3-E18
Character mistake: When Gordon and O'Hara show Barbara the slides of Batman and Robin's previous exploits, the last slide shows the Batmobile being hit with mines. Gordon says they're chasing King Tut, but it's actually from Catwoman's "Better Luck Next Time".
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