While Gotham City Burns (2) - S1-E30
Visible crew/equipment: When Batman and Robin use the Batmobile's high energy radar to probe the giant cookbook, and also when they use the Bat-magnet, the reflection of the moving boom mic/pole is visible on the bubble windshield. (00:11:40)
While Gotham City Burns (2) - S1-E30
Continuity mistake: While Bookworm is at stately Wayne Manor he hands Aunt Harriet a book, and when she opens it Harriet and Alfred are gassed unconscious. In the next closeup of the rare book encased in glass, its open pages have colorful illustrations, but in the next shot the open pages have only plain text. (00:09:30)
While Gotham City Burns (2) - S1-E30
Visible crew/equipment: After Gotham City PD show up at the giant cookbook with the Dynamic Duo trapped inside, when Gordon, O'Hara, and the officers are standing at the cookbook's cover, the chalk T-mark and other chalk marks are visible on the ground. (00:15:50)
While Gotham City Burns (2) - S1-E30
Other mistake: When Batman realises what needs to be done, the camera turns to Robin with a sixty second clock on screen. Supposedly, Batman did all his actions within sixty seconds to save Robin. Robin was saved after two minutes and three seconds.
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