15 Things You Never Knew About 'Indiana Jones and the Last Crusade' on its 30th Anniversary

It's been 30 years since "Indiana Jones and the Last Crusade" hit theaters. Or as some fans refer to it, "The only good Indiana Jones sequel." Wherever this blockbuster hit falls on your Indy rankings,  celebrate this big anniversary by learning more about the making of "The Last Crusade."

1. When Steven Spielberg and George Lucas first began discussing ideas for a third Indiana Jones movie, Lucas suggested using a haunted mansion as a major set piece. However, Spielberg rejected the idea, having recently completed work on 1982's "Poltergeist."

2.Chris Columbus wrote a very different sequel screenplay in 1985 called "Indiana Jones and the Monkey King," which revolved around Chinese folk hero Sun Wukong and the fabled Garden of Immortal Peaches.

3. Spielberg was once slated to direct both "Big" and "Rain Man" but had to drop out of both projects due to his work on "The Last Crusade."

4.River Phoenix was Harrison Ford's personal choice to play the young Indy, as Ford had previously worked with Phoenix on 1986's "The Mosquito Coast."

5. Similarly, Spielberg always envisioned Sean Connery playing Henry Jones, Sr. Spielberg has long held a desire to direct a James Bond movie, and casting Connery as the elder Jones was a way of reflecting the Bond franchise's influence on Indiana Jones.

6. In another Bond tribute, the gun used to shoot Henry Sr. in the temple is a Walther PPK, Bond's trademark weapon.

7. Connery didn't play Henry Sr. in the prologue sequence. The character was instead played by Alex Hyde-White, with Connery later dubbing over his lines.

8. Spielberg also wanted legendary British actor Laurence Olivier to play the Grail Knight, but Olivier had become too ill by the time of filming and passed away not long after "The Last Crusade" hit theaters.

9. While the treasure hunter who gives Indy his trademark fedora is only listed as "Fedora" in the credits, the original screenplay reveals him to be Abner Ravenwood, father of Karen Allen's character Marion Ravenwood.

10. The Nazi uniforms used in the book-burning sequence are actually authentic WWII relics. Designer Joanna Johnston discovered a cache of old uniforms while scouting in Eastern Europe.

11. The thousands of rats used in catacombs scene are a mix of live creatures and animatronic props. The production team had to specially breed the live rats in order to ensure none of them would be carrying communicable diseases.

12. In the scene where Donovan's wife appears and reminds him he's neglecting his guests, a character can be heard in the background playing "The Imperial March" from "The Empire Strikes Back" on the piano.

13. Donovan's iconic death sequence is the very first all-digital composite sequence in film.

14. The horses used in the final scenes outside the temple were loaned by none other than King Hussein of Jordan.

15. While Spielberg admitted he made "The Last Crusade" for less than glamorous reasons (including the need to complete a three-picture deal with Lucas), he's also named the sequel as his favorite movie in the series.