Trivia: Viggo Mortensen was so impressed with the horse his character Aragorn was riding in the movies, that he bought it from its owner. It had to be flown back to New Zealand for reshoots. While filming, he would sometimes sleep in the stable with the horse, to earn its trust. Trust was particularly important for the scene when the horse kneels and lies near him at the river.
Trivia: It is Christopher Lee's voice mixed with Ian McKellen's that is heard when Gandalf speaks while he's hidden by the white light in Fangorn Forest. It is also Lee's voice heard when King Theoden is speaking to Gandalf, while he is still under Saruman's power. Confirmed on the commentary.Super Grover
Trivia: Gimli's prosthetic forehead had become detached by the time they were to shoot him in this scene. The senior prosthetics supervisor got on his stomach behind Gimli and pulled on a rope that was attached to the back of the prosthetic in order to pull the wrinkles out of Gimli's forehead and keep it in place. Art Director Ben Price is the very dead twitchy Uruk-hai that Gimli is sitting on. Commentary, extended DVD. (01:38:50)Super Grover
Trivia: In the Extended Edition, when Merry and Pippin begin to grow, Merry says "But I've always been the tall one," Monahan and Boyd said in the commentary that quite often that is how the crew referred to them because they kept confusing Monahan and Boyd so they were the "tall one" and the "short one."Jack's Revenge
Trivia: Elijah Wood's (Frodo) sister Hannah, is in the film. She's the lone, blonde, lost-looking girl, clutching her shawl with her left hand, at the beginning of the shot in the Glittering Caves, at Helm's Deep when the women and children go in. She is also on the stairs for Theoden's return. (00:51:55)
Trivia: Usually when the people in charge of the scenery need to make a life-size model of something, they create the smaller version and then create the life-size one as much like it as possible. However, it was the other way around with Helm's Deep: the life-size model was built first (with an easily collapsible wall) and the miniature for it was built later.
Trivia: In Helm's Deep, when women and children retreat to the caves, look closely at the children. They're the same actors as the Hobbit children listening to Bilbo's story of the trolls at his birthday party in "Fellowship" and they're in RotK as well. They're the children of director Peter Jackson and writer Fran Walsh.
Trivia: Many of the major shots depicted in the movie are duplicates of Alan Lee's illustrations, in the LotR books, that had been published years before. In many shots, the actors were positioned in the same poses, as the drawings in the books. One example is, when Frodo pulls Gollum's head back and holds Sting up to his throat. (00:10:40)Super Grover