The Joker Trumps an Ace (1) - S1-E25
Continuity mistake: The Joker reveals himself by throwing off his cape, which drops to the floor behind him. But when the shot cuts, the cape instantly disappears. (00:00:50)
The Joker Trumps an Ace (1) - S1-E25
Revealing mistake: In Commissioner Gordon's office, when Batman opens Joker's gift the genie figure begins to inflate, and in the overhead shot the stunt's covered air hose is visible at the bottom of the screen. In the next shot Batman pops the figure causing it to deflate, and the wire at the top of the figure's head is visible as it descends. (00:07:05)
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