The Zodiac Crimes (1) - S2-E37
Revealing mistake: When Joker enters Commissioner Gordon's office at GCPD, he's pointing a wand at Gordon and Chief O'Hara. In the shot facing Joker when he lets go of the wand, the wires at both ends of the wand are visible. (00:01:15)
The Zodiac Crimes (1) - S2-E37
Revealing mistake: After Joker's goons kidnap Crustash, the opera singer, Penguin tries to sneak off, and when Batman and Robin use javelins to capture Penguin, the glistening stunt wire attached to the javelin is visible in the wide shot. (00:18:15)
The Puzzles Are Coming (1) - S2-E31
Revealing mistake: While The Puzzler and his baddies are at Artemus Knab's penthouse, across the street from Commissioner Gordon's office, when Puzzler decides he will launch the plane himself, the wire attached to the top of the plane is visible. (00:01:15)
The Puzzles Are Coming (1) - S2-E31
Revealing mistake: At the old balloon factory, when Puzzler throws the model airplane with a poison tip at Batman, on his upper arm we can see the protruding outline of the rectangular base to which the small airplane is attached. (00:22:00)
Tut's Case is Shut (2) - S2-E8
Revealing mistake: While Chief O'Hara is outside on the ledge of the top floor, King Tut commands him to use the flagpole to do acrobatics. When O'Hara obeys Tut, the vertical wire at the end of the flagpole is visible. (00:08:20)
Walk the Straight and Narrow (2) - S2-E2
Revealing mistake: When the armored truck with the ten million is hit, during this scene we can see stunt wires for some of the arrows used by Archer and his goons. (00:09:00)
Walk the Straight and Narrow (2) - S2-E2
Revealing mistake: At the start, while Archer and his goons are riding toward Batman and Robin who are tied to the stakes, when the Dynamic Duo use their Bat-springs the stunt wires lifting them are visible. (00:03:05)
Shoot a Crooked Arrow (1) - S2-E1
Revealing mistake: In Commissioner Gordon's office, just as Gordon tells Dale that with Batman and Robin on their side no harm will befall the money, the top of the set is visible at the top right corner of the screen. (00:06:25)
Shoot a Crooked Arrow (1) - S2-E1
Revealing mistake: At Archer's underground hideout, Batman and Robin are strung up by their thumbs, but in fact the stunt wires that lead to their cloaked backs are visible. (00:21:40)
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)
Revealing mistake: While Batman and Robin are tied up and suspended over the enormous candle dipper vat, there are stunt wires leading to under their capes. (00:21:00)
Better Luck Next Time (2) - S1-E20
Revealing mistake: When Batman dodges the tiger by using metal claws to climb the wall, the stunt wires lifting him are visible. (00:03:00)
When the Rat's Away the Mice Will Play (2) - S1-E12
Revealing mistake: When Riddler and his Rats have been caught near the end, during the ensuing fight Batman throws one of the Rats, and as he goes flying across the room we can see the stunt wires. (00:21:55)
The Penguin's a Jinx (2) - S1-E4
Revealing mistake: When Penguin uses the large umbrella to slide across the Penguin line, at the top of the umbrella there's a pulley wheel, but when he reaches Dawn's penthouse terrace there's only a small loop at the top of the large umbrella. The same thing happens when Swoop follows Penguin on another large umbrella. (00:13:40)
Fine Feathered Finks (1) - S1-E3
Revealing mistake: After the huge rooftop umbrella is launched onto the street there's a small umbrella hanging from its handle, and when Batman uses his Batarang to swing towards the huge umbrella's shaft, his stunt wires are visible. (00:18:45)
Revealing mistake: At the start, when Joker has sprung himself from prison, there are three shots of the giant spring, and the wires holding up the platform at the top are visible. In the third shot, one of the wires even glistens for a moment as it moves. (00:02:35)
The Penguin's a Jinx (2) - S1-E4
Revealing mistake: When the Penguin orders his hook to be fired, it barely moves, then suddenly takes off. If you look closely at the hook before it moves, the connecting wire used to pull it out of frame can be seen. (00:13:30)
Smack in the Middle (2) - S1-E2
Revealing mistake: After Batman tosses his Batarang up to get to Molly, the lifting wire attached to him is plainly visible.
Nora Clavicle and the Ladies' Crime Club - S3-E19
Revealing mistake: Not only does Batman's solo flute play two music tracks at once, it also keeps on playing after he's taken it out of his mouth. (00:20:00)
The Riddler's False Notion (2) - S1-E32
Revealing mistake: The film can Riddler hands Van Jones supposedly contains his silent movie. But the hollow thump, obvious light weight and lack of the distinctive rattle a film reel would make, all reveal that the can is actually empty. (00:19:00)
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