Audio problem: When the camera shows the flames of the exhaust, the accompanying sound is wrong. The turbine starting up was played when the flames were seen, instead of the roaring sound effect.
The Great Train Robbery (2) - S3-E22
Revealing mistake: At the Batcave, when Batman programs the skywriter drone and switches it on, the two stunt wires are visible as it heads out of the Batcave. (00:15:40)
The Great Train Robbery (2) - S3-E22
Visible crew/equipment: When Shame has finished reading Batman's skywriting message, as he says, "Darned if I won't be there," the shadow of the boom mic dips into view at the top of the green door, at the right side of the screen. (00:17:20)
I'll Be a Mummy's Uncle - S3-E23
Visible crew/equipment: When King Tut runs back up the shaft and encounters Batgirl, Commissioner Gordon, and Chief O'Hara, he is reveling giddily in the truth he has discovered. Then, when Batman and Robin show up, their chalk T-marks are visible on the ground. (00:21:10)
I'll Be a Mummy's Uncle - S3-E23
Plot hole: After the rock falls on King Tut at the end giving him amnesia, Batman explains how the rock fell. He says Tut raised his voice three decibels above high C. Decibels are a measure of volume, while pitch is a measure of frequency: the two are not directly related. This mistake was done in other episodes of Batman also, such as when Joan Collins played the villain.
The Joker's Flying Saucer - S3-E24
Continuity mistake: Batman and Robin both leap into the Batmobile and roar out of the Batcave. But the stock shot used after that shows Batman alone in the car. (00:03:10)
The Joker's Flying Saucer - S3-E24
Character mistake: Vertigris tells Joker he planted a bomb in the Batmobile while it was parked in front of City Hall/Police HQ. Only in this instance, it wasn't. It was parked in the alley out back, the better to hide his bomb-planting from public view, so it's strange that he'd forget this. (00:08:15)
The Joker's Flying Saucer - S3-E24
Continuity mistake: Aboard Joker's flying saucer, Alfred and Batgirl are sitting three feet apart, then shoulder-to-shoulder, then apart again, depending on the shot. (00:20:50)
The Joker's Flying Saucer - S3-E24
Plot hole: A time bomb is placed under the dashboard of the Batmobile and goes off inside the batcave. Much of the batcave is ruined, including fallen I-Beams, but the Batmobile has no damage to it even though the bomb was planted in it.
The Joker's Flying Saucer - S3-E24
Other mistake: Just before the final fight scene, Alfred hits his head on the door of the spacecraft while exiting, kind of like the Storm Trooper in Star Wars, reacts for a second and then keeps going on with the scene as if nothing happened.
The Entrancing Dr. Cassandra - S3-E25
Visible crew/equipment: While Batman and Robin are at GCPD, Batman decides to use the library to research occult sciences, and when it cuts to Cassandra and Cabala returning to their hideout they walk over to the table, and behind them we can see the chalk marks on the floor by the door, where they previously stood. (00:05:15)
The Entrancing Dr. Cassandra - S3-E25
Visible crew/equipment: After Batman discovers Cassandra's true identity in the alchemy book, he takes a call from Commissioner Gordon on his cute portable Batphone, then he and Robin head to Spiffany's. When it cuts to Spiffany's, just as narrator William Dozier says, "Gotham City's fashionable 15th Ave," the actor's white marks are visible on the floor under the table. Then we see Cassandra's and Cabala's white T-marks when they walk in. Next, upon the Terrific Trio's entrances, we see their T-marks as well. (00:08:25)
The Entrancing Dr. Cassandra - S3-E25
Visible crew/equipment: After Alfred has placed the two-dimensional Terrific Trio into the Three-Dimensional Bat-Restorer, when they all walk out of the chamber, two chalk T-marks are visible on the floor. First we see Batgirl's T-mark and then Robin's. (00:16:50)
The Entrancing Dr. Cassandra - S3-E25
Continuity mistake: The Batmobile returns to the Batcave by remote control. It's facing left when we get a brief, three-second shot of Batgirl talking to Batman and Robin. In the very next shot, the Batmobile has instantly turned itself around and is facing right. Its turntable (which was actually pushed manually by stagehands under the platform) didn't work quite that fast. (00:18:05)
Minerva, Mayhem and Millionaires - S3-E26
Visible crew/equipment: At the start, in the two consecutive scenes with millionaires William Dozier and then Howie Horwitz, while they're being treated to Minerva's renowned scalp massage, the chalk T-mark is visible on the floor at the lower left side of the screen, and in the Horwitz scene Minerva's small mark is also visible on the floor behind the spa chair. (00:00:45)
Minerva, Mayhem and Millionaires - S3-E26
Visible crew/equipment: Minerva tells Freddie that if she'll get the diamonds from the Wayne Foundation vault, he can fence them. When it cuts to Commissioner Gordon, Batgirl, and Chief O'Hara pacing the floor, three small white tape marks are visible on the rug in front of the coffee table, where each of them stop and turn on their marks. (00:05:35)
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