Times & Citizen has written an article about the Cardington hangar used to film Batman Returns. The hangar is currently being prepped for The Dark Knight:

More recently, the shed was converted into a studio by Hollywood giant Warner Brothers, which leased it for the filming of Batman Begins in 2004.{@@@newline@@@}{@@@newline@@@}The Gotham City set was built inside, brought to life by dozens of local people who landed parts as extras.{@@@newline@@@}{@@@newline@@@}The Times & Citizen understands Warner Brothers has renewed its lease on the shed for a further 12 months, and could now be in residence until December next year.{@@@newline@@@}{@@@newline@@@}Intriguingly, signs of activity at the shed in recent days, and glimpses of cables and a lighting gantry through the massive opened doors, have prompted speculation the hangar is being freshly rigged for another film shoot.{@@@newline@@@}{@@@newline@@@}Top of the rumour list is the sequel to Batman Begins, the title of which was unveiled by Warner Brothers last month as The Dark Knight.{@@@newline@@@}{@@@newline@@@}Reports suggest filming is due to begin early next year, with Christian Bale once more squeezing into the rubber suit as Batman, and heartthrob Heath Ledger set to grin and bear it as The Joker.