According to this thread on Quora, there are some hidden secrets you should look out for on your next trip to Disneyland.
1. Look for Walt Disney's light at the Main Street firehouse — the light that never goes out.
2. Ask for the special tender seat on the Disneyland railroad.
3. Go see the park bench where Walt Disney originally conceived of the idea of Disneyland.
In the foyer of "Great Moments with Mr. Lincoln," there is a park bench where Walt came up with the idea while watching his daughters play. This is the Griffith Park bench, and nearby is one of the actual carousel horses that his daughters used to ride.
4. If you ask nicely, you can ask to pilot the Mark Twain Riverboat.
5. When the park first opens, go to the Main Street Station and ask for a reservation to ride in the Lilly Belle train car.
6. Ride in the purple teacup in the Mad Hatter ride — it spins the fastest.
7. If you try on a hat in the Mad Hatter gift shop, you might glimpse the Cheshire Cat in the mirror.
8. Look out for Walt and Roy Disney's initials, which are formed in the wrought-iron railing above the queue to the Pirates of the Caribbean.
9. For the adventure-seekers: Employ "the Goat Trick" for an extra-thrilling ride on Big Mountain.
10. There are two fun interactive things you should do at Indiana Jones.
1) Do the opposite of what the sign says and pull the bamboo pole. There will be a loud booming noise and it will seem as though the ceiling is caving in.
2) Do the opposite of what the sign says and pull the rope. It makes an unseen worker "fall" and voices will cry out from the well.
11. For a cool souvenir, ask for a death certificate when you enter the Haunted Mansion.
12. Listen for the hidden sounds.
13. When you're getting off the Jungle Cruise, ask a cast member for a free map.
14. If you touch the apple at Snow White's Scary Adventures, the queen will laugh maniacally.
15. In one of the buildings in Fantasyland above the Snow White attraction, the Evil Queen appears in a window for only a few seconds every few minutes.
16. Creepy fact: There's just one real human skull left at Pirates of the Carribean.
