Batman claims to have taken a "sacred vow" to never allow any stranger to enter the Batcave. However, in the very first episode, The Riddler's moll, Molly, not only entered the Batcave (even though Batman saw though her disguise as Robin) but fell into the atomic pile and was killed.
In later episodes, henchwomen Pauline, Venus, and Lydia Limpett were taken to the cave by Batman, as was the Catwoman. He allowed the Penguin and the Joker, along with their henchmen, to stow away in the Batmobile's trunk and enter the Cave. In the motion picture, Penguin was taken to the cave, disguised as Commodore Schmidlap, and bought along a crew of dehydrated henchmen. Finally, both Commissioner Gordon and Batgirl were taken to the Batcave by Batman.
In later episodes, henchwomen Pauline, Venus, and Lydia Limpett were taken to the cave by Batman, as was the Catwoman. He allowed the Penguin and the Joker, along with their henchmen, to stow away in the Batmobile's trunk and enter the Cave. In the motion picture, Penguin was taken to the cave, disguised as Commodore Schmidlap, and bought along a crew of dehydrated henchmen. Finally, both Commissioner Gordon and Batgirl were taken to the Batcave by Batman.