The Clock Tower was Oracle's main base of operations in Batman: Arkham Knight. Besides Oracle, several wealthy residents were known to reside within the building according to the offical novelization.
The Clock Tower was located between the Chinatown and Cauldron districts on Bleake Island, visible from almost everywhere on the city.
Before Arkham Knight Incident
After Barbara Gordon chose the site as her base of operations, the building was retrofitted by Bruce Wayne's construction company, allowing the building to withstand even the most dangerous of natural disasters. Reportedly, only the richest Gotham residents could afford to stay inside the building.
At some point, a cataclysmic earthquake devastated much of Gotham City. As a result of the upgrades, Clock Tower happened to be one of several buildings to survive intact, saving Barbara and the rest of the building's residents. Bruce Wayne's construction company later capitalized on the success of the building to bid for contracts that would allow them to retrofit the rest of Gotham City's skyscrapers.
Arkham Knight Incident
During the Arkham Knight incident, the Clock Tower served as Oracle's base of operations as well as her hideout, as she had lied to her father about having evacuated Gotham with the other citizens. The Tower, while serving as Barbara's home, also housed a Batcomputer, which would emerge from the floor and activate when Batman engaged a scanning device hidden in a bust of Shakespeare. In one corner of the room was a hidden compartment where Barbara's old Batgirl suit was stored. Another corner housed a computer and some living arrangements, suggesting that this was also Barbara's home. On the bookshelf next to the Shakespeare bust was a photo of Barbara and her fiancee, Tim Drake.
Batman and Barbara used the Clock Tower computer to analyze Scarecrow's fear toxin and find out where it was being manufactured. After pinpointing the toxin's origin to the ACE Chemicals factory off the coast of Bleake Island, Batman set off to shut it down. During his infiltration of the factory, however, Scarecrow had the Arkham Knight's militia kidnap Barbara in an attempt to mentally tear Batman down piece by piece.
Batman later escorted Commissioner Gordon to the Tower. Before Jim arrived, Batman briefly hallucinated the inside of the Clock Tower as Barbara's apartment where he seemingly witnessed Barbara's crippling at the hands of The Joker, though quickly shook it off. Just as the commissioner arrived, Batman engaged the Batcomputer before Gordon's eyes, revealing that Barbara worked for Batman. Angered, Jim blamed Batman for Barbara's predicament and stormed out of the tower himself intent on rescuing Barbara without Batman's help. Batman later used the Tower's CCTV to find out who had taken Barbara.
During the Heir to the Cowl case, the Tower was where Batman arranged to meet with Azrael after the latter completed his tests. Prior to their final meeting, Batman analyzed Azrael's memories with the Batcomputer, learning that the Order of St. Dumas had subtly brainwashed Azrael into their slave with intent to have him kill Batman and replace him as Gotham's protector. At this point, Azrael would either attempt to fulfill his mission and end up subdued and incarcerated, or would destroy the Sword of Sins that Batman kept stored there, thank Batman for restoring his will and leave the Tower to take down the Order.
After Barbara was rescued from Scarecrow's clutches, she learnt that the Arkham Knight's militia was attempting to destroy the Clock Tower's servers and lock her out of the Batcomputer and its archives kept there. Batman promptly went to the Tower and defeated the militia, foiling them and retaining access to the systems there.
- Oracle seems very fascinated with the Gotham City Police Department as within her apartment are two police coats, a cop hat and a GCPD poster next to her computer.
- It's also unknown if Jim lives with Barbara or not, though given the coats and his over-protection of her it seems they may live together. However, this is debunked by the fact there's only one bed and Jim could accidentally find the Batcomputer.
- In the concept art of the Clock Tower shows a table in the center and Penguin in his Arkham City design.
- Barbara will be in the tower until Ace Chemicals explodes.
- If Azrael chooses to leave the Clock Tower without grabbing his sword from the shelf, it will remain there for the rest of the game.
- The elevator is shown only to go from the third floor to Oracle's apartment, this ether means there's two elevators or just an oversight.
- Why there are several computer cubicles on the top floor is unclear. They are likely Barbara's as either spares or extra processing power for the Batcomputer as its unlikely an office could be usable in a clock tower.
- The Batcomputer security system hidden in a bust of Shakespeare is a reference to the 1966 Batman TV series, where the access device to the Batcave was hidden in a bust of Shakespeare in a similar fashion.