Originally, there was only a secret tunnel that ran underground between Wayne Manor and an old barn where the Batmobile and Batplane were kept. Later, in
Batman #12 (August-September 1942),
Bill Finger mentioned "secret underground hangars". In 1943, the writers of the first
Batman movie serial gave the Caped Crusader a complete underground crime lab and introduced it in the first chapter entitled "The Bat's Cave".
Bob Kane, who was on the movie set, mentioned this to Bill Finger who was going to be the initial scripter on the BATMAN Daily Newspaper strip. Finger included with his script, a clipping from
Popular Mechanics that featured a detailed cross section of underground hangars. Kane used this clipping as a guide, adding the crime lab, stalactites, stalagmites and bats. Thus, the Dark Knight's creators introduced the definitive Batcave in the
Batman "
dailies" on October 29, 1943;
[1] and in January 1944, the Batcave made its comic book debut in
Detective Comics #83
[2][3]
In these early versions it was just a small cave with a desk,
filing cabinets and
laboratory. Behind the desk, the Batman's symbol was carved into the rock with a candle in the middle of it. With time the cave expanded along with its owner's popularity to include a trophy room, supercomputer and forensics lab.