Many of the attractions at the Disney Theme Parks and Universal Studios have backstories, but you have to look in books and promotional materials for the parks to find them. Some of them are explained by voiceover artists over intercoms or through video packages aired while you're waiting in line, but not everyone pays attention to them — or they speed through the line too fast to even see them.
For an example, Revenge of the Mummy at Universal Studios Florida is based around the concept that you're participating in a filming of another Mummy movie. If you take the Express line, you'll go through too fast to even figure this out, leaving some Orphaned References behind (such as the crew member wrapped up like a mummy, and a cameo from Brendan Fraser at the very end).
While The Amazing Adventures of Spider-Man explains the gist of its plot during the queue — the Sinister Six have stolen the Statue of Liberty using a levitation ray, and the Daily Bugle decides to send in tourists to cover the scoop while Spider-Man saves the day — it is never properly explained where Doctor Octopus' levitation ray came from. He claims that he created it himself, but a tie-in comic book reveals that this was not the case, and that he actually stole it from Stark Industries.
Disney is an odd case of this, as their official policy regarding a ride's backstory is that it is whatever the cast members working there that day decide it is. Most rides have a generally accepted story that most cast members will stick to, but any details are subject to change at a moment's notice, and some of the best parts come from certain cast members deciding to change it up a bit. The Haunted Mansion is particularly notorious for its extensive backstory, which was created by cast member anecdotes being meticulously documented and pieced together by fans.
The Blizzard Beach water park at Walt Disney World has a unique backstory. One day, Florida was hit with a freak snowstorm and it was decided to create the state's first ski resort. When all the snow melted and the plans were to be cancelled, they saw the Ice Gator sliding down the slopes and they decided to make it a water park.
Batman the Ride at Six Flags is a notable example; the story is that Batman wants to clean up Gotham City, as told in the queue line, but since the ride itself is a standard roller coaster, there's no follow-up to this plot.
