Walt Disney himself supervised the design of the Pirates of the Caribbean attraction at Disneyland, and deliberately set out to make it the most spectacular ride ever. It was a major accomplishment that set the standard for experience-based theme park rides ever since. When it opened in 1967, the final cost was $15 million, as much as the rest of the park combined. But no other park ever recreated one of Disneyland’s details: the real skeletons.
After creating such realistic mayhem, the design team was disappointed by "the faux skeletons of the period," which they found "just too unconvincing," reports former Disney producer Jason Surrell in his book Pirates of the Caribbean: From the Magic Kingdom to the Movies. So they hit up their friends at UCLA Medical Center and got some grisly props from the anatomy department. Eventually, as fake skeleton technology improved, "a new generation of Imagineers" replaced the real ones, which "were later returned to their countries of origin and given a proper burial," assures Surrell.
Or did they? The replacements were done gradually, and rumors still exist about the few skeletons or skulls that remain of the human type. Some people have even identified which ones they are. Read about them at Atlas Obscura.
(Image credit: Flickr user Anna Fox)