The Batcave was Batman's underground base of operations, and secondary home where he could find solitude.
Bruce first discovered the cave system below Wayne Manor when he fell into them as a child, and returned to the caves after his decision to model his crime fighting persona after a bat.
Initially only using the caves to store his equipment, Bruce eventually began to construct a secret headquarters within the caves to better operate independently and in secret.
The Batcave was accessed through a rotating wall in Wayne Manor's silver closet, the only room in the mansion that was kept locked. The cave could also be reached via a secret tunnel system from Bruce Wayne's Office at Wayne Enterprises, through which he rode down in a capsule.
In addition to the standard housing of the computer and equipment, the cave was originally intended to play a larger role in this film. Alfred revealed a second level to the cave, and an amnesia stricken Bruce explored the cave to jog his memory after an attack by Two-Face. Those scenes, however, were cut from the final film. The cave was also shown to have a canal inside of it, which provided access to the sea for water-based vehicles. The cave featured a rotating turntable that rose out of the floor that held the Batmobile, and a large dome-like structure where Bruce's Batsuits and gadgets were stored.
The cave featured a multitude of flashing lights, mostly in neon. On the whole, that Batcave was similar to that in Batman Forever, only it was more garish in its decoration. A capsule that contained Robin's Redbird motorcycle rose out of the floor, and a long tunnel lined with neon lights lead out of the cave. The turntable that held the Batmobile retured, but was a more elaborate fashion.