1969s ''Valley of Gwangi'' was Special Effects Master Ray Harryhausen's last film. While somewhat a silly script (Cowboys vs Dinosaurs) with ''B''-Movie Actors, the Film is worth it for Ray's ''stop motion'' Allosaurus aka ''Gwangi''. The soundtrack with it's campy full Orchestra is also worth it. Somewhat disliked by Critics, ''Gwangi'' would acquire a Cult following status for some years after. Hardly any US Television did not show The Film on their Friday or Saturday Night ''Creature Features''. The Plot is set in the early 20th Century at a Carnival in Mexico (much of the live action was filmed there). Local Legend tells of a mythical cavern inside which Monsters live, in particular one ''Gwangi'' rumored to be a God. The Owner, whose Carnival is lagging in money ''buys'' a specimen that turns out to be a living Prehistoric miniature Horse (extinct for 50,000 years). Perhaps The Legends are true. So, The Carnival launches an Expedition in search of this mythical Cave.
In reality what is found, is that somehow a Prehistoric ecosystem thrived, sealed deep in a Cave (many miles long). The Expedition finds a living Allosaurus. Subduing The Monster (drugged), a massive promotion campaign is set for Mexico City and the unveiling of Gwangi. Of course, Gwangi escapes and tears up Mexico City. Corralling The Beast inside a burning Cathedral the collapsing building crushes to death our Monster. The cautionary tale......''Best to leave well enough (or even Dinosaurs)....alone!'')