Audiences around the world are joining Peter Jackson on a last journey to Middle Earth with the release of the third and final "Hobbit" film, "The Hobbit: The Battle of the Five Armies," on December 17.

The film may be the last foray into J.R.R. Tolkien's world for quite some time, since the rights for "The Silmarillion" and other connected works still rest with the Tolkien family.

In honor of the last Hobbit film — which comes complete with its own #OneLastTime hashtag campaign — here are 50 things you might not know about "The Hobbit: An Unexpected Journey," "The Hobbit: The Desolation of Smaug," "The Lord of the Rings: The Fellowship of the Ring," "The Lord of the Rings: The Two Towers" and "The Lord of the Rings: The Return of the King.”

Related: 27 best J. R. R. Tolkien quotes

Related: Jackson leaves Middle Earth with 'The Hobbit'

Related: 'Five Armies' brings the Hobbit trilogy to a fun but indulgent finish

Related: 'The Hobbit: The Battle of the Five Armies': 3 points for parents

'The Hobbit: An Unexpected Journey'
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The first phone call Peter Jackson and his team made about making movies of "The Hobbit" and "The Lord of the Rings" was to film executive Harvey Weinstein.

In their initial pitch, the filmmakers said they’d like to make “The Hobbit” as one film, and then — if it was successful — make “The Lord of the Rings” as two movies, released six months apart.

That's not quite how it worked out...

'The Hobbit: An Unexpected Journey'
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Sound designer David Farmer once did a presentation for his daughter’s first grade class where he had his daughter “roar," and then he transformed it into a dragon’s roar. When it came time to create Smaug’s roar, Farmer decided to see if that sound clip would work, and it did.

The first time you hear Smaug roar — when he’s attacking Dale and Erebor in “An Unexpected Journey” — that sound comes from the roar of Farmer's daughter mixed with the roars of a hungry pig.

'The Hobbit: An Unexpected Journey'
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The original set for Hobbiton was built to be taken down once filming was complete on the "Lord of the Rings" films. In rebuilding Hobbiton for “The Hobbit: An Unexpected Journey,” though, filmmakers built the set to last — real bricks, real wood, real stone — so now visitors to New Zealand can come and see the village in real life.

There are 44 personalized hobbit holes in Hobbiton.

'The Hobbit: An Unexpected Journey'
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The 13 dwarves in “The Hobbit” each come to Bilbo’s house wearing a colored hood: Dark green (Dwalin), red (Balin), blue (Kili and Fili), purple (Dori and Nori), brown (Oin and Gloin), yellow (Bifur and Bofur), pale green (Bombur), grey (Ori) and sky blue with a large silver tassel (Thorin).

In honor of this, the inside of the dwarves’ cape hoods in the films feature the colors mentioned by Tolkien.

'The Hobbit: An Unexpected Journey'
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Three of the dwarves — Dori (Mark Hadlow), Gloin (Peter Hambleton) and Bifur (William Kircher) — also play talking trolls Bert, William and Tom (respectively), who capture the dwarves before being turned to stone by the sun. The three actors performed the roles using motion capture technology.

'The Hobbit: An Unexpected Journey'
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Actor Andy Serkis, who played Gollum/Smeagol in the “Lord of the Rings” trilogy, was the first person in the makeup chair for “The Hobbit” films, reprising his role as a 60-year-younger Gollum/Smeagol.

'The Hobbit: An Unexpected Journey'
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The first two weeks of filming were devoted to capturing the iconic game of riddles between Bilbo Baggins and Gollum/Smeagol in the heart of the Misty Mountains.

Peter Jackson said he felt sorry for actor Martin Freeman, because not only was Freeman immediately dropped into Middle Earth, but he was also immediately acting opposite Gollum/Smeagol and Andy Serkis in the motion-capture outfit.

'The Hobbit: An Unexpected Journey'
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Filmmakers shot for 266 days over the course of 18 months on “The Hobbit” films, which was the same number of days they shot on the “Lord of the Rings” films.

The cast did their jobs with the expectation that they would be making two movies. However, on the day of the wrap party, they were informed they'd be making three instead.

'The Hobbit: An Unexpected Journey'
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Richard Taylor of Weta Workshop said artists did 1,000 illustrations for the “Lord of the Rings” films. For “The Hobbit” films, they’ve done some 9,000.

'The Hobbit: An Unexpected Journey'
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The last sound from “An Unexpected Journey,” when Smaug opens his eye, is six alligator growls all layered together.

'The Hobbit: The Desolation of Smaug'
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If you are particularly observant, you might notice that one of the chess pieces from Beorn's house — a bear-shaped King — shows up in “An Unexpected Journey” when Bilbo is rifling through a chest in search of his journal.

'The Hobbit: The Desolation of Smaug'
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Lee Pace, who plays Thranduil, the king of the Mirkwood elves and father of Legolas, is two years younger than Orlando Bloom, who plays his son.

'The Hobbit: The Desolation of Smaug'
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To shoot the scene where the dwarves float away from Mirkwood in empty barrels, they did some filming on the Pelorus River in New Zealand, and then did additional filming on a fake river set.

The fake river set featured an 80-meter circuit of whitewater rapids powered by two V8 engines, which the dwarves rode around in their barrels. The actors referred to it as a fairground ride or “Jacksonland.”

'The Hobbit: The Desolation of Smaug'
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The wigs for the dwarves were made out of yak hair, which meant that they repelled water. Even when the dwarves would go under the water, they would pop back up looking dry. Filmmakers had to put a special kind of gel on the wigs to make them look wet — even though they (and the actors) were wet.

'The Hobbit: The Desolation of Smaug'
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Actor Ryan Gage auditioned for a hobbit and a dwarf, and was originally cast as Drogo Baggins, Frodo’s father. After that role was cut, he was recast as Alfrid, the lecherous right-hand man of the Master of Laketown.

'The Hobbit: The Desolation of Smaug'
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Comedian Stephen Colbert, who is a huge Tolkien fan, makes a cameo appearance in Laketown as a spy keeping an eye on Bard the Bowman’s activities for the Master of Laketown.

'The Hobbit: The Desolation of Smaug'
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Luke Evans, who plays Bard the Bowman in “The Desolation of Smaug,” also plays his ancestor Girion, who tried and failed to kill Smaug during the dragon’s attack on Dale.

The role of Bard is the first Evans has ever taken where he was asked to use his native Welsh accent.

'The Hobbit: The Desolation of Smaug'
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Bard the Bowman was given three children as part of his character development for the “Hobbit” films. Two of those children — Sigrid and Tilda — are played by Peggy and Mary Nesbitt, the daughters of Jimmy Nesbitt (Bofur the dwarf).

Bilbo’s mother Belladonna Took appears briefly in the extended edition of “An Unexpected Journey.” She is played by Sonia Forbes-Adam, who is married to Jimmy Nesbitt.

For those keeping track, that means that Jimmy Nesbitt is a dwarf, married to Bilbo’s hobbit mother, and the two are parents of two Laketown humans.

'The Hobbit: The Desolation of Smaug'
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Actor Benedict Cumberbatch, who provided the voice for the Necromancer in “The Desolation of Smaug,” wanted to infuse the character’s lines with a diabolic, inhuman quality. He did this by learning his lines backwards phonetically, and then performing them that way.

Cumberbatch also performed the voice of and motion capture for the dragon Smaug.

'The Hobbit: The Desolation of Smaug'
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Prior to filming motion capture footage for Smaug, actor Benedict Cumberbatch spent time at the London Zoo studying iguanas, Komodo dragons and other reptiles.

Swedish actor Mikael Persbrandt, who played Beorn in “The Desolation of Smaug,” also studied animals to help him prepare for his role as the mythic shapeshifter. His choice of animal, however, was not a lizard, but a wolf.

'The Lord of the Rings: The Fellowship of the Ring'
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The opening narration for “The Fellowship of the Ring” is performed by Cate Blanchett, in the role of Galadriel, but that wasn’t always the case. Originally filmmakers planned to have Frodo provide that narration, and then their plan later changed to Gandalf.

They ultimately chose Galadriel because of the agelessness of elves, and because she could provide a bookend for the films by appearing at the beginning and end of the trilogy.

'The Lord of the Rings: The Fellowship of the Ring'
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At Bilbo’s birthday party, the audience is introduced to the mischievous hobbits Merry and Pippin when they steal a firework from Gandalf’s cart only to have it blow up in their faces.

On the day of filming, nobody told actors Dominic Monaghan or Billy Boyd that the firework was going to blow up, so the shriek you hear from Boyd in the movie is his automatic and very real reaction.

'The Lord of the Rings: The Fellowship of the Ring'
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According to Peter Jackson, Fran Walsh, and Philippa Boyens, the cake at Bilbo’s birthday party was made out of polystyrene and covered in so many candles that it eventually caught fire. Actor Ian Holm was doing such a good job, though, that they let the cameras keep rolling. Reportedly the fiery dessert can be seen in wide shots.

'The Lord of the Rings: The Fellowship of the Ring'
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As Bilbo leaves Bag End, he turns and drops the One Ring onto the floor, leaving it for Frodo to find. A magnetic floor was created to ensure that the ring could not bounce, therefore communicating its weight.

'The Lord of the Rings: The Fellowship of the Ring'
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The haunting, eerie screams of the Ringwraiths are courtesy of co-writer/producer Fran Walsh. When the filmmakers couldn’t find the right sound for the Ringwraiths, she decided to show them what she thought it should sound like. They recorded her demonstration, liked it, and used it in the film.

Speaking of Ringwraiths — after the four hobbits take a shortcut to mushrooms and find themselves hiding from a Ringwraith, watch for the Ringwraith to magically walk out of the tree.

'The Lord of the Rings: The Fellowship of the Ring'
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Viggo Mortensen, who played Aragorn in the "Lord of the Rings" trilogy, was not originally cast in the role. After filmmakers realized they needed to find a new actor to play the part, they made the decision to call Mortensen, who decided to do the role at the urging of his son Henry. Mortensen’s first day on set was the fight with the Ringwraiths in the ruins of Weathertop.

'The Lord of the Rings: The Fellowship of the Ring'
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Boromir’s speech at the Council of Elrond beginning with, “One does not simply walk into Mordor” — a line that will live forever in Internet memes — was given to him the night before filming. Actor Sean Bean didn’t have time to learn the entire speech, so he had the lines written out and held them on his lap to glance at occasionally.

'The Lord of the Rings: The Fellowship of the Ring'
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Bill the pony was not in the film for a long time due to the logistical difficulties associated with transporting a pony around for traveling shots of the Fellowship, but Peter Jackson really wanted him in the film. The problem was solved when filmmakers created a pantomime puppet pony. In many scenes where the fellowship is walking, particularly the scene in the snow on Caradhras, you’re seeing the phony pony rather than a real horse.

The line outside of Moria where Aragorn sends Bill away, saying, “Don’t worry, Sam, he knows the way home,” was added at the studio’s request, so audiences would know Bill survived.

'The Lord of the Rings: The Fellowship of the Ring'
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During the scene in Moria where Gimli is mourning the fate of the dwarves who tried to reclaim the mountain and Gandalf is reading Ori’s journal, Aragorn is shown almost entirely in profile. The day before shooting, Viggo Mortensen had gone surfing with the actors playing the hobbits, and had gotten hit in the face with a surfboard. The right side of his face was swollen and couldn’t be shown.

'The Lord of the Rings: The Fellowship of the Ring'
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Filmmakers shot footage of the first meeting of a younger Aragorn and Arwen. It was originally going to be used as a flashback in Lothlorien, but they instead used that time to build the relationship between Aragorn and Boromir, to heighten the emotional impact of Boromir’s death.

'The Lord of the Rings: The Two Towers'
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In the scene where the three hunters — Aragorn, Legolas and Gimli — encounter the smoldering pile of dead orcs and assume that the hobbits Merry and Pippin have been slain, Aragorn kicks an orc helmet, screams and falls to his knees. Actor Viggo Mortensen broke his toe when he kicked the helmet, but filmmakers liked the performance so much that they used it in the film. They did, however, stop filming that day, so as the scene continues in the film, what audiences see was actually filmed the next day.

'The Lord of the Rings: The Two Towers'
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Peter Jackson tends to flip scenes whenever he needs a character to be looking in a different direction or facing a different way. These flipped scenes are visible occasionally, particularly in the scenes in Fangorn with Aragorn, Legolas and Gimli. To spot these changes, keep an eye on Legolas’ brooch — when it changes directions, it indicates a flipped scene.

'The Lord of the Rings: The Two Towers'
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The city of Edoras was built on a hill in New Zealand, and a helicopter rig was set up to film big sweeping shots of the set. However, because it was so windy, the shots were not great. The shot used in the film when the heroes arrive was actually shot when filmmakers were building the set, and was only meant to show Peter Jackson its progress. Using those shots in the film required filmmakers to remove construction cranes and safety fences, and to finish building the set digitally.

'The Lord of the Rings: The Two Towers'
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Bernard Hill, the actor who portrays King Theoden of Rohan in “The Two Towers,” was one of the actors filmmakers considered for the role of Gandalf.

In transforming the old, bewitched King Theoden into the younger King Theoden, makeup artists created four different stages of makeup — one old, one young and two in between — and filmmakers then morphed the four together. The oldest stage of makeup required up to 10 hours in the makeup chair.

'The Lord of the Rings: The Two Towers'
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In “The Two Towers,” Legolas’ CG double makes a dramatic leap onto his horse during the warg attack — a shot that usually gets cheers from the audience. The shot was not originally planned, though. Peter Jackson realized during post-production that they had never gotten a shot of Orlando Bloom jumping onto a horse because Bloom had cracked a rib that day during filming. At the time of post-production, Bloom was shooting another film and couldn’t shave to do a pick-up shot of Legolas jumping onto a horse. Filmmakers went with the CG double because they had no other choice.

'The Lord of the Rings: The Two Towers'
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Actor Jed Brophy — perhaps better known to audiences as Nori from "The Hobbit" — appears in multiple scenes in the "Lord of the Rings" films. Not only is he the orc that laughs after Aragorn falls off the cliff during the warg battle in "The Two Towers," but he’s also the orc that wants to eat Merry and Pippin at the beginning of the film (“Why can’t we have some meats?”) the soldier who finds Theodred in the water in the extended edition of “The Two Towers,” and a horse stunt rider, among other characters.

'The Lord of the Rings: The Two Towers'
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The first day on set for both Bernard Hill, who played King Theoden, and Miranda Otto, who played Eowyn, was the scene where King Theoden and his riders arrive at Helm’s Deep following the fight with the wargs. Hill says they knew they had just lost Aragorn in the film, but they didn’t know how or why. They were reacting to an event that would be filmed two and a half years later.

'The Lord of the Rings: The Two Towers'
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In trying to convince Treebeard the ent to take the two hobbits south toward Isengard rather than north to safety, actor Billy Boyd says he was basically instructed to, “Waffle on a lot of rubbish.” The line he came up with was, “The closer we are to danger, the farther we are from harm — it’s the last thing he’ll expect.”

'The Lord of the Rings: The Two Towers'
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Tolkien's book distinctly says there is a “Black Gate of Mordor" — no plural — but there are two gates in the film because of a typo in the information given to the folks at Weta Workshop.

'The Lord of the Rings: The Two Towers'
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In the final scene of “The Two Towers,” as Gandolf, Legolas, Aragorn, Gimli and King Theoden are sitting on horses and discussing Sauron’s anger and the battle for Middle Earth that is to come, you can see Eomer’s body double to the right of King Theoden, rather than Eomer himself. Peter Jackson said they were going to replace the body double’s head, but they never got around to it.

'The Lord of the Rings: The Return of the King'
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As the third movie in the trilogy, “Return of the King” inherited scenes planned for earlier films, including the Isengard sequence where Gandalf, King Theoden, Aragorn and others confront Saruman and find the Palantir, and the scene where Smeagol gets the One Ring.

Originally the film was meant to begin with a shot pulling back from the opening to the Paths of the Dead and rushing across the plains of Edoras to show Aragorn waking from a nightmare.

'The Lord of the Rings: The Return of the King'
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In "The Return of the King," there’s a brief shot of Eowyn standing outside and looking over Edoras. The shot is an example of Jackson tweaking things to get what he needs — the original was shot pulling away from the actress, but the shot in the film was reversed so it moved in toward the actress. In reversing the footage, filmmakers were required to digitally paint out soldiers who were suddenly walking backward.

'The Lord of the Rings: The Return of the King'
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Jed Brophy — again, Nori, from the “Hobbit” films — played several roles in the “Lord of the Rings” films, but he wasn’t the only Brophy family member to get some screen time. His son appears as the son of Aragorn and Arwen in Arwen’s vision of the future.

'The Lord of the Rings: The Return of the King'
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The story of Figwit is long and complicated — and entirely a creation of fans.

“Figwit” is the nickname for an elf who appeared in the council of Elrond scene in “The Fellowship of the Ring” right after Frodo volunteered to take the ring to Mordor. The nickname stands for, “Frodo Is Great, Who Is That?!”

The extra who won fans’ hearts — actor and musician Bret McKenzie — was later given a bigger part in “The Return of the King,” thanks to “Figwit” fans. He appears as the elf who tells Arwen they must continue their journey to the Gray Havens.

He also appears in “The Hobbit: An Unexpected Journey,” but this time, with an official name: Lindir, Elrond’s assistant.

'The Lord of the Rings: The Return of the King'
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The last thing ever shot for "The Return of the King" — skulls rolling across the floor in the Paths of the Dead — was shot after the movie won the Academy Award for Best Picture.

'The Lord of the Rings: The Return of the King'
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Royd Tolkien, the great-grandson of J.R.R. Tolkien, appears in the Osgiliath battle scene as a Gondorian ranger handing out spears.

'The Lord of the Rings: The Return of the King'
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Co-writer Philippa Boyens recalled hearing actor Billy Boyd (Pippin) singing during a cast karaoke night, and found a way to work his singing abilities into the script as Faramir and his men ride out on a fruitless attempt to retake Osgiliath.

Boyd was asked to write the song, and said he tried to come up with a song that felt old, like something the hobbits’ grandparents would’ve sung, or a song from before the time when the hobbits came to the Shire.

'The Lord of the Rings: The Return of the King'
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Because filmmakers didn’t want to make actor David Wenham (Faramir) lie on top of a pyre for days while filming the scenes surrounding the pyre, they built a silicon dummy to use for distance shots. If there’s a close-up of his face, it’s the actor; if the camera is far away, it’s the dummy.

'The Lord of the Rings: The Return of the King'
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Sean Astin, who played Sam Gamgee in the “Lord of the Rings” films, auditioned for the role using the scene after Frodo is poisoned by Shelob the spider. In the scene, Sam begs Frodo, “Wake up. Don't leave me here alone. Don’t go where I can’t follow.”

'The Lord of the Rings: The Return of the King'
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Viggo Mortensen joined the cast of “The Lord of the Rings” primarily at the urging of his son Henry, but years later, Mortensen got his revenge — Henry is the first orc that Aragorn kills during the Battle of Pellenor Fields outside of Minas Tirith. Mortensen wanted to use his son in the scene, so filmmakers put Henry in an orc costume and let his dad kill him.