As someone who has actually worked at Walt Disney World in all 4 parks, I have some problems with the current BuzzFeed post going around.

1. There are not tunnels under “Disney World”. There are tunnels under the Magic Kingdom, and a small tunnel under Epcot. They really shouldn’t be called tunnels either, but utilidors.
2. Yep, nobody sells gum except a few resort shops outside of the parks. BuzzFeed, I guess you couldn’t do your one job right and find a relevant GIF for this one?
3. “Hidden Mickeys” is the right term to use here. The biggest hidden Mickey is at Disney’s Hollywood Studios, see if you can find it using a park map although it was partially ruined by a certain new weenie.
4. Ok, they got one completely right. My addition here is in the bottom of almost every trash can is a container of Vobane, a saw-dust like material. We are prepared for your protein spills.
5. The Cinderella Castle Suite is not secret at all, it was a huge part of the year of a million dreams marketing campaign.
6. Illegal, questionable. The Haunted Mansion is clearly the most popular location for this, followed by Pirates of the Carribean. Just because the ride is dark doesn’t mean the operators can’t see you people.
7. If you want to get technical, Prince Charming’s Regal Carrousel was not an opening day attraction. It was known as Cinderella’s Golden Carrousel up until 2010.
8. There was no Doc because there are only six obvious subdivisions of the parking lot on each side, and clearly everyone always forgets Doc anyways. Additionally, pre-villains, there was the fab five minus Mickey plus Daisy and Chip and Dale on one side, and six Dwarfs on the other.
9. The biggest use of the smellitzer technology is on Main Street. Notice your urge to buy popcorn as soon as you walk into the park?
10. This one is not right. Yes, the bright colors do complement the surroundings and make them pop in photos, but that is not why the exact colors were chosen, and it was not Kodak who did this. Main Street USA is red to fit along with the concept that the whole park experience is designed like a movie. The Main St train station is the curtain, the red street the red carpet, the names on the store windows the opening and closing credits. The color of the ground also is closely matched to each of the 7 lands, and goes neutral in between. This helps the guest subconciously tell where they are in the park. AllEars has a nice article about pavement in all the parks.
11. It’s not just in Pooh that there is a nod to a previous attraction in that space. Indiana Jones Adventure at Disneyland was built over an old parking lot, and the name of that lot can be found in the queue.
12. Yep.
13. Also very accurate.
14. While this may have been the imagineers’ original design, the guest-friendly story is that it is a portion of the street turned to dirt by horse traffic.
15. A surprising amount of maintenance goes into the lawn and the whole mansion to make it look abandoned. They still clean everything, they just are very careful to not remove the artificial cobwebs.
16. Up until the latest Haunted Mansion queue re-imagining, the “ring” in the ground was actually just the broken off bottom of a queue stanchion. Imagineering finally made the ring story official with the latest rennovation.
17. Even Snopes got this one wrong. It was never a thing to drop to the ground, as first of all it is a safety hazard, but it also has show concerns too. Think of what a small child would think if characters appeared to be dead on the ground.
18. I’ve heard this one for years, but I’ve never seen it cited properly. I see freedom of speech issues with it not being allowed to be displayed.
19. There’s also a phone in the hat store in town square that will play messages. But sadly most of these have not worked properly for years.
20. Ok? Yay.
21. The model needs serious dusting.
22. While this was technically right at one point, it’s been used as storage and staging space for many years now. It was never meant to be a basketball court, but a hoop was installed unofficially years ago.
23. Not any more. Space 8 is now the millenium village, and it will not be taken out any time soon as it is far to lucerative for convention services and is used as a staging kitchen during the Food and Wine festival.
24. This isn’t a fact about Disney parks, but a fact about a history souvenir…
25. Go watch Illuminations from the backside of the pub, you’ll thank me later.
26. The massive building in the back of the China pavilion was also designed to hold a ride originally.
27. Volume wise, yes. Actually, no.
28. Just wait until Avatar land opens and then we will see what they butcher the logo with.
29. Remember when McDonald’s seemed to sponsor everything? Now they are barely even on property, with the location by the All-star resort not loved by WDW management.
30. …turned upside down!
31. The amount of prop re-use around property is amazing once you start noticing it. Also, you can find really interesting things if you take the back road between the Epcot main parking lot and the cast log.
32. The Great Movie Ride has so many hidden things in it you can find something new every time.
33. Every prop in the room where you watch the pre-show is tied in to an episode of Twilight Zone

If you are interested in facts like this, I highly recommend the official Keys to the Kingdom tour.