The Batcave is first referenced in Batman #12 (June 10, 1942).
The Batcave is a fictional subterranean location appearing in American comic books published by DC Comics.
It is the secret headquarters of the superhero Batman, whose secret identity is Bruce Wayne, consisting of a series of subterranean caves typically depicted as being beneath his residence, Wayne Manor.
The Batcave was Batman and Robin’s secret base of operations, where they often investigated crime cases and kept their arsenal for crime-fighting. Similar to the Earth-Two counterpart, the Batcave was connected to Wayne Manor by a large staircase.
However, Batman decided to improve this feature and built an elevator to connect both places. He also adapted a new secret entrance for the Batmobile.
The cave had previously been located in an abandoned barn, but Batman changed it and switched the secret entrance to a hidden door on a mountain side, which was activated from the remote controls of the Batmobile