When Bruce Wayne began his crusade this space was limited to storing only one Batsuit.
Batman Returns Edit
The Vault was later upgraded to a large closet space to store 2nd Generation Batsuits.
Batman Forever Edit
Bruce later expanded his Vault to a large oval space to store his 3rd Generation Batsuits and equipment. Later Dick Grayson enters the Vault to retrieve his Flying Grayson costume which was placed next to the Cowl of one of the third Generation suits. During the attack on Wayne Manor, this vault was destroyed by The Riddler (along with the majority of the 3rd Generation suits) during his assault on the Batcave.
Batman & Robin Edit
Bruce later recreated a new Vault in the Batcave and also remade his 3rd Generation suits and storing them to this vault. His partner Robin also has a costume Vault in the Batcave. Alfred could be seen standing next to the third Generation suit in Bruce's vault.