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)
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