Revealing mistake: In this episode and the next one, Robin's stunt double is very obvious from the back, especially in the scene where they enter the Hall of Fame museum.
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)
Revealing mistake: To free himself from the Joker's goons, Batman throws a gas capsule on the floor. Two things; first, the Joker is instantly asphyxiated by a lot of smoke, but when the henchmen let Batman go in the next shot, the puff of colored fumes has barely started to rise, and the Joker is further away. Second, the capsule that Adam West throws with panache on the ground and that should generate the noxious cloud can be seen actually bouncing back up after his energetic toss. (00:15:30)
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