Christian Bale actually stood on those high rise ledges.
Christian Bale could have used a stunt double, but he chose to stand on a ledge of the 110-story Sears Tower in Chicago, which stood in for a Gotham high rise. He did the same thing for similar scenes in Hong Kong. "How often do you get a chance to do that in a Batman costume? I'm not letting anybody else do that," he said in a 2008 interview with The Early Show on CBS. "The thing that was kind of disturbing but enjoyable was how comfortable I felt," he added. "It literally took 30 seconds."
Christian Bale did not ride the Batpod.
That Batpod was apparently way harder to operate than it looks. "It was deemed too dangerous," Bale said in an interview at the time. "They needed me in one piece to finish the damn movie." The actual prop was expected to fetch between $80,000 and $110,000 when it was auctioned off in 2016. It ended up selling for three times that.
Heath Ledger wanted Batman to hit him for real.
In October 2017, Joe McCabe published the book 100 Things Batman Fans Should Know & Do Before They Die, which included a collection of newly unearthed interviews the pop culture reporter had conducted around the time of the film's release, as well as an interview done with Ledger a couple of months before his death. Bale says their first scene together was the Joker interrogation scene. "I was saying, 'You know what, I really don't need to actually hit you,'" he recounted. "And he's going, 'Go on. Go on. Go on...'" As Bale put it so well: "his commitment was total."
There is only one Dark Knight deleted scene.
Heath Ledger passed away in January 2008. His work was finished on The Dark Knight and there isn't much else to see that isn't out there. Nolan is famously efficient about what he spends time shooting, with little to nothing left over in terms of deleted scenes. There is only one "extra" scene from The Dark Knight that we know about. It's the Joker escaping in a getaway car, just after storming Bruce Wayne's penthouse. A production still is the only evidence of this scene we've seen.
The Dark Knight includes a nod to Heath Ledger's daughter.
In the scene where the Joker visits Two-Face in the hospital, the nametag on his nurse's uniform reads, "Matilda." It's a tribute to Ledger's daughter with actress Michelle Williams. Matilda was just two years old at the time of her father's death.