The Eiffel Tower's original permit had a demolition clause built in

The Eiffel Tower's original building permit had an expiration date on it. Twenty years, then down it comes, hauled off in pieces, the Champ de Mars handed back to Paris looking the way it did before 1889.

It was never meant to be permanent. The tower went up as the centerpiece of the 1889 World's Fair, and the contract Gustave Eiffel signed with the city was explicit: after twenty years, ownership reverted to Paris, and the city had every right to tear it down. 1909 was the deadline. At just over 300 meters, it was nearly double the height of anything else humans had ever built, and plenty of Parisians thought that alone was reason enough to take it down on schedule.

Forty-seven Parisians who wanted it gone before it opened

In February 1887, while the tower's four legs were still just foundations in the mud of the Champ de Mars, a petition ran in the newspaper Le Temps. Forty-seven names were attached to it — composer Charles Gounod, writer Guy de Maupassant, novelist Alexandre Dumas fils, and, in a detail we like more than we should, Charles Garnier, the architect of the Paris Opera, objecting to somebody else's architecture.

"...in the name of French taste and art... against the erection, in the very heart of our capital, of the useless and monstrous Eiffel Tower."

Eiffel wasn't some unproven newcomer they were right to be suspicious of. By 1887 he'd already engineered the internal iron skeleton holding up the Statue of Liberty, which had been standing in New York harbor for a year without a word of complaint from anyone. Part of what made the Paris petition sting was exactly that: an engineer the rest of the world already trusted with landmarks was getting run out of his own city's newspapers.

They called it an "odious column of bolted metal" and compared it to a factory chimney — not entirely unfair, given the tower is held together by roughly 2.5 million rivets and not a single weld. It didn't work; construction was too far along to stop. Maupassant, the story goes, ended up eating lunch in the tower's restaurant on a regular basis after it opened, because it was the one place in Paris where he didn't have to look at it.

The wire that talked the executioner out of it

By the early 1900s, with the 1909 deadline closing in, Eiffel needed the tower to be useful for something, not just tall. In 1903 he gave the summit to army engineer Gustave Ferrié for wireless telegraphy experiments. Ferrié reached French forts 400 kilometers away, then a naval base in Tunisia, then — by 1908, a year before the demolition clause kicked in — a signal 6,000 kilometers out. Paris didn't just quietly let the deadline slide. On January 1, 1910, the city handed Eiffel a new concession, not for another twenty years but for seventy.

We went looking for some kind of marker of this at the base of the tower and mostly came up empty. A guard near the north pillar shrugged when we asked about a radio room — the wireless station itself is long gone, and what's left of the tower's radio-era infrastructure is a WWI-period room built into the underside of the structure that today, we're told, doubles as a break room for staff. No plaque, no line for tourists. You have to already know it's there.

By the time the First World War broke out, that same antenna was intercepting German radio traffic for the French army — the exact "useless" structure the 1887 petition wanted torn down had become a piece of military infrastructure the country couldn't do without. It's a strange kind of vindication: not that Paris changed its mind about how the tower looked, but that it stopped mattering once the tower proved it could do something the petition's signatories never imagined asking of a monument.

The tower that survived because it proved itself useful is now the most photographed monument on Earth, and the demolition clause that almost ended it in 1909 is the part every glossy brochure leaves out.