Batcave

The Batcave is Batman's hideout to put all of his vehicles and do his detective work

Origins
Wayne Manor was built over an elaborate network of caves in northern Gotham City. Colonies of bats call them home. In the 1980's, Bruce Wayne proposed to Andrea Beaumont above them. The awakened bats swarmed upwards past the couple. Upon further exploration, Wayne was impressed to discover the vastness of the caves. However, Alfred Pennyworth greeted him with bad news. Beaumont broke off the engagement and fled the States with her father. Soon after, Batman took form and went on his first night of patrol. Hidden in Wayne Manor, there are three ways to enter the Batcave: an access elevator and a staircase behind the grandfather clock and main book shelf in the study. Batman began to outfit the cave and modeled it as an almost exact replica of the Gray Ghost Lair, from television. It became known as the Batcave.

Characteristics
The main section houses a state of the art $50 million system called the Batcomputer. Nearby is a mechanical garage, engineering area, aircraft hangar, gymnasium, boat dock, trophy room, displays of various weapons, and a lower level chemical and forensics lab. The Batcomputer is linked to a video surveillance system used to keep tabs on all of Gotham City. The Batboat is docked below in the cave's lowest point on an underground river that feeds into Gotham Bay. The Batcave has several security measures, including knockout gas and later, an electrified blast door reinforced with a layer of solid steel. Bruce Wayne's wrist watch is keyed into the Batcomputer's alarm system and is used to summon his partners in an emergency situation. After realizing the threat Superman could pose, Batman hid a cache of Kryptonite in a room behind the display case of costumes. It can only be accessed by Bruce Wayne after a full biometric scan

Others that been in the Batcave
Aside from Alfred, Dick Grayson, Barbara Gordon, and Robin, other allies that were privy to and entered the Batcave were Gray Ghost, Superman, Wonder Woman, The Flash, Green Lantern, J'onn Jonzz, Hawkgirl, Static, and Gear. Terry McGinnis discovered the Batcave by accident 50 years later after seeing a bat stuck in the study's grandfather clock. In equal measure, the Batcave has been infiltrated by Ra's al Ghul, Ubu, Randa Duane, the Batman duplicant/H.A.R.D.A.C., Phantasm, Thanagarians, Inque, Ian Peek, and the Joker. The Man Bat, an orphan named Frog, one of Mr. Freeze's henchmen, and one of Thomas Blake's cultists were taken against their will to the Batcave for either treatment or interrogation. In a hyper timeline, Chronos and the Jokerz destroyed the JLU Watchtower and the Batcave. The remaining members of the League and Bruce Wayne gathered at a makeshift base of operations in the abandoned Hamilton Hill High School. This event cease to be when Batman reset the timeline. Likewise, in the now erased Vandal Savage hypertime and parallel universes, the Batcave is set up in a similar manner.