1. The scenes for 4 Privet Drive were originally shot on an actual street. They only ended up making houses because they didn't have access to the house for reshoots.
2. The graphics team hand-wrote thousand of letters but then found out that they were too heavy for the owls, so they had to make them again.
3. Even then it took the owls six months to learn how to carry them.
4. The doors at Gringotts actually work, it took three months to make the door they used for Bellatrix's vault.
5. There were over 20,000 packages and goods in the windows of Diagon Alley.
6. Crew members used ropes and wrenches to bend and twist the set once it was fully assembled to give it that whimsical look.
7. Daniel Radcliffe, Rupert Grint, and Emma Watson didn't see the Great Hall until they filmed the Sorting Hat scene.
8. There were actually two murals on each end of the Great Hall.
9. There was only one staircase built for the movies.
10. Many of the portraits in Hogwarts were based on cast and crew. For example, this is production designer Stuart Craig.
11. Hagrid's beard was made of six different hair pieces.
12. And things got stuck in it all the time, including live bats.
13. There are two Hagrid's hut sets.
14. The crew hired baby ostriches to sit in the baskets at Hagrid's but by the time they came they were too big to fit.
15. There were over 588 sets built for the eight movies.
16. There are over 1,000 bottles in the Potions classroom.
17. And all the potions they drank were actually soup.
18. Most books in Dumbledore's office are phone books that have been rebound and covered in dust.
19. The Gryffindor sword was a real sword that was purchased at an auction.
20. The Horcruxes were designed by props concept artist Miraphora Mina, whose experience was rooted in her mother's work as a jeweler.
21. The hands on the Weasley's clock are actually scissors with photos of the actors pasted into their handles.
22. All the furniture placed in the front towers in the Ministry of Magic was made out of cardboard.
23. Over 40 kittens were brought in for a "kitten photo shoot" to be featured in the dishes in Umbridge's office.
24. The Knight Bus was so top heavy that 4 tons of weight had to be added to the bottom so it didn't fall over.
25. Each wizard chess piece weighed almost 500 pounds.
26. There were 60 types of goblins made.
27. Dobby's ears were based on an art department dog named Max that used to sit under the designers' desks.
28. Every exterior shot of Hogwarts was made using this model. It took seven months and 40 people to make it.
29. It took three months alone to create the bridge.
30. They used salt for snow.
31. And every single shingle was laid by hand.
Now that's magic.
