[[CoolVersusAwesome Cowboys versus dinosaurs!]]

''The Valley of Gwangi'' is a 1969 American film about cowboys fighting an Allosaur (not a Tyrannosaur, though it is often mistaken for one). The film is known for its StopMotion Animation creature effects provided by Creator/RayHarryhausen.

The idea had already been done years earlier in the movie ''Film/TheBeastOfHollowMountain'' but "Gwangi" is the better known of the two. 'Gwangi' was originally conceived by Willis O'Brien, the man who did the special effects for ''Film/KingKong1933''.

Sometime near the turn of the century, a cowgirl named T.J. hosts a traveling rodeo show, currently parked near a desert town. Her former fiancé, cowboy "Tuck" Kirby, wants to buy her out, but T.J. has hopes that her latest discovery -a tiny horse- will boost attendance to the show. A British paleontologist named Bromley declares the creature to be an Eohippus, a prehistoric horse.

The horse came from an area known as "The Forbidden Valley". A gypsy woman claims that it should be returned or they will all suffer the wrath of a being she calls "Gwangi". Later Bromley helps a group of gypsies steal the horse, (he hopes to follow it to its home). Tuck, T. J. and several of their cowboy helpers set out to recover it, and follow them into the valley.

It turns out the valley is a LostWorld that has a variety of prehistoric creatures including a Pteranodon that attacks them, but the cowboys kill it. They are then attacked by the titular Allosaur. Gwangi battles a styracosaur and wins. The cowboys try to capture the monster by lassoing it around the neck and pulling it down with several horses. However they only succeed when Gwangi knocks itself out while pursuing them.

The cowboys take it back to the town where it is to be put on display in T.J.'s show. However on the opening night one of the Gypsies sneaks in and begins to unlock Gwangi's cage in an effort to free it. He gets killed for his troubles, and Gwangi escapes, killing Bromley and a circus elephant in the process.

Eventually Gwangi, Tuck, T.J and a Mexican boy named Lope end up in a cathedral which catches on fire. They (the humans, that is) manage to escape and lock the door behind them, trapping Gwangi in the burning building which then crumbles around it. The movie ends as everyone watches Gwangi die.
!! Tropes in this film:

* AbsentMindedProfessor: Paleontologist Doctor Bromley.
* ArtisticLicensePaleontology: Even Harryhausen himself seemed confused as to exactly what kind of dinosaur Gwangi was supposed to be.
* BringItBackAlive
* CaliforniaDoubling: The movie was shot in Cuenca, Spain.
* CharacterDevelopment: Tuck loses his greedy selfishness over the course of the movie. Interestingly, T.J. briefly develops it.
* ChildrenAreInnocent: Lope, by virtue of being the most honest character among the entire cast. Sure he conned Tuck, but he really needed the money.
* CoversAlwaysLie: See that poster up there? The one with the green dinosaur? Yeah, Gwangi is [[AmazingTechnicolorWildlife bright purple]] and T.J. has red hair, not black.
* DomesticatedDinosaurs: Attempted twice, succeeds with the ''Eohippus''. But fails with Gwangi himself.
* DumbDinos: Gwangi is of the marauding-monster variety - he leaves an elephant he kills uneaten before targeting humans.
* EscapedAnimalRampage
* EverythingsBetterWithDinosaurs: Though, Gwangi's victims might think otherwise.
* {{Greed}}: Both Tuck and Bromley catch a bad case of this when they see the ''Eohippus''. T.J. isn't immune either, once Gwangi is caught she planned on using him to make a fortune in her show. Needless to say, in the end nobody got what they wanted.
* InfantImmortality: The little boy Lope survives both the ''Pteranodon'' attack in the middle of the movie, and Gwangi's rampage near the end. Pretty much anyone else who crosses the Dinosaurs' path aren't so lucky.
* InformedSpecies: Gwangi is supposed to be an ''Allosaurus'', but he looks more like a ''TyrannosaurusRex'' with three fingers. Though this was a common mistake back then.
* {{Jerkass}}: Tuck and Carlos.
* KillItWithFire
* LivingDinosaurs: Gwangi and some other fauna of the "Forbidden Valley".
* TheLoad: T.J., though [[TooDumbToLive Professor Bromley]] may be a better example.
* LostWorld: The "Forbidden Valley" where Gwangi comes from.
* NeckSnap: Carlos kills the Pteranodon this way.
* PrehistoricMonster: Gwangi himself, of course, but also a KidnappingBirdOfPrey ''Pteranodon'' and even the ''Styracosaurus'' hassles the humans!
* UsefulNotes/{{Romani}}: As typical of the times, presented as superstitious, sinister, and TooDumbToLive.
* RuleOfCool: The whole point of the movie.
** Allosaur versus Styracosaur!
** Allosaur versus Elephant!
** Ray Harryhausen himself has expressed that the idea of cowboys lassoing a prehistoric monster several magnitudes larger, stronger and heavier than what those ropes should be able to hold is more than a little silly, but also provided visuals that were simply too entertaining to pass up.
* {{Redubbing}}: The actress playing T.J. had such a thick Israeli accent, she had to be redubbed.
* SeldomSeenSpecies: The discovery of the small horse-like ungulate ''Eohippus'' is what triggers the plot.
* ShoutOut: Later on, Gwangi appears not on the warpath and he scratches the side of his head, just as the ''Tyrannosaurus'' in ''Film/KingKong1933'' did.
* {{Spexico}}: The movie was shot in Cuenca, Spain.
* StockDinosaurs: ''Allosaurus'' (or possibly ''TyrannosaurusRex''), ''Ornithomimus'', ''Styracosaurus'' and ''Pteranodon'' are all stock.
* TheUnreveal: The movie never explains how prehistoric creatures (from various eras separated by millions of years to boot) had survived in the valley. [[RuleOfCool Does anyone really care about finding that out?]]
* StarringSpecialEffects
* SuperPersistentPredator: Gwangi kills other dinosaurs and an elephant but leaves them to go after humans. Maybe it really was evil... Or this was based on something that [[RealityIsUnrealistic happens with real-world predators]], Gwangi saw the movement of prey animals constantly, all around him, so he kept attacking out of confusion and fear. "Didn't I kill you already?"
* ''TyrannosaurusRex'': Though billed as an ''Allosaurus'', Gwangi doesn't really look like one.
* UngratefulBastard: Gwangi, twice humans risk themselves to help or protect him, and twice he shows his gratitude by eating them.
* WellIntentionedExtremist: The gypsies, especially the old woman who claims the little horse should be returned to the "The Forbidden Valley" or everybody will suffer a curse, to the one Gypsy who sneaks around and tries to free Gwangi from his cage. Heck let's face it, almost ''all'' the gypsies.
* WhatEverHappenedToTheMouse: T.J.'s Eohippus just disappears after leading the characters to the valley. It's never seen or even mentioned again.