25 Things You Probably Didn't Know About Indiana Jones

12. "No Trousers" - The Last Crusade

The studio sets were so hot on the final film in the original trilogy that both Sean Connery and Harrison Ford filmed the entire Zeppelin scene without trousers on.

11. Spielberg Hated The Crystal Skull Aliens

In an interview with Empire magazine in October 2011, director Steven Spielberg admitted that he felt obligated to put the alien element into The Kingdom Of The Crystal Skull because of his friendship with George Lucas, whose idea it was, despite him not liking that aspect of the plot: "I am loyal to my best friend. When he writes a story he believes in - even if I don't believe in it - I'm going to shoot the movie the way George envisaged it."

10. The Melting Paramount Mountain

Each of the four Indiana Jones features a Paramount logo visual trick. In Raiders Of The Lost Ark, the Paramount mountain dissolves into the mountain in the Peruvian jungle, while in Temple of Doom it dissolves into a mountain on a gong. In the third movie, the mountain dissolves into a mountain in the American West, and finally in Crystal Skull, in a more comic move, the logo dissolves into a gopher mound.