Eiffel had this wild idea that radio seemed like it could become the next big communications device. And since radios needed a tall place to send long-range messages, the world's most hated -- but tallest -- structure seemed like an ideal spot for a radio tower. And it was: Eiffel stuck a radio transmitter at the top of the tower and offered it to the French Ministry of War as a communications base, enabling their messages to make it all the way across the English Channel. With war quickly building up with Germany and Italy, the radio proved to be a useful wartime instant messaging system.
"It's the Lunchtime Request Hour. Call in some Skynyrd!"
So the radio became the tower's saving grace, and just five years later, it proved to be well worth saving when it became the key transmission point to jam German radio communications, stalling their advance just north of Paris. From then on, the Eiffel Tower has stayed put, with the last serious attempt to dismantle it being in 1967, when a crazed Montreal mayor thought it would be the perfect thing to "borrow" for the World's Fair. But the tower remained, saving many a Hollywood production from having to print the word "Paris" on the screen every time the city is shown.