Dark Knight Rises Rumors says:
A bunch of pictures have been released showing what we assume will be the Batcave for The Dark Knight Rises. They are actually pictures of the Turda Salt Mines in Romania, but it’s likely that the mines will be a stand-in for the Batcave.
It’s also already been confirmed that they are building a small-scale Batcave at Warner Bros.’ studios, but many of the scenes may be shot at the Turda Salt Mines. Just by taking a quick glimpse at some of these pictures, you can immediately see why they picked this place as the Batcave for The Dark Knight Rises.