Visible crew/equipment: While Batman and Robin are tied to the spit and rotating, when Batman says, "If we could just shake this turn spit pole loose," in the next shot note the shadow of a crew member moving their arm up, at the lower right corner of the screen. (00:03:35)
Visible crew/equipment: When Minstrel and his henchmen race down the stairs, the sound pole rigging shadow is moving at the very top of the screen. (00:04:00)
Continuity mistake: While Batman is telling Octavia that she can go free, his hands are either straight down at his sides or clasped together at chest level, depending on the shot. (00:06:15)
Continuity mistake: Between takes at the end of the final fight scene, most of the chairs shift positions around the table, the wooden partition screen that fell over during the scuffle has somehow folded itself, and a white cloth that was draped over one of the chairs has disappeared. (00:22:00)
Continuity mistake: At the end, when Minstrel is cornered by the Dynamic Duo, he pulls out his sparking remote unit. After being told it won't work, as O'Hara cuffs him, the unit that was in his hand disappears.
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