When the Eiffel Tower was inaugurated at the 1889 Paris Exposition, it was derided by some of the city’s leading artists as useless, monstrous and barbaric. By objective measures it was the tallest structure in the world, a claim it would retain for four decades, built to celebrate the triumph of industrialization, technological prowess and the centenary of the French Revolution. To this day, the monument remains one of France’s foremost landmarks and a tourist attraction that draws some 7 million visitors per year.None of it could have happened if it had been torn down, as almost happened in the tower’s early days. Or if Montreal had succeeded in borrowing it—which the city’s mayor tried to pull off for its own Expo in 1967. (Would it really have been returned and reconstructed in its original location?)Indeed, if the “walls” of the Eiffel Tower could talk, they’d have a host of very good stories to tell, many unknown to the general public. So with the help of Savin Yeatman-Eiffel, a fifth-generation descendant of Gustave Eiffel, the engineer-turned-businessman who built the tower, Bloomberg got a tour and gained insight into facts (and secrets) you never knew to ask about.It wasn’t always that color.What color is the Eiffel Tower? The answer changes almost day to day. It’s not, as many would think, the metal’s natural, weather-worn bronze hue, but rather a hodgepodge of paint shades that have been in a constant state of evolution as old layers chip and new paint gets applied. At this point, just under half of the tower is covered in a custom-made hue called “Eiffel Tower Brown”; the rest is either newly painted with another color or getting scraped down. Variations over the years haven’t all been subtle either. Seven different color makeovers have been given to the monument, and the latest choice likely won’t be the last.In Gustave Eiffel’s lifetime alone, the tower fully changed color five times. The metal parts were a bright “Venetian red” before they were assembled, and then painted with a thick coat of reddish-brown for the opening. A few years later the whole monument was painted ochre brown, and then in 1899 it got what might arguably have been its most spectacular look: a five-tone fade ranging from yellow-orange at the base to pale yellow at the top.If you can’t quite picture any of that, you may soon be able to. After a study of all the tower’s colors, architect Pierre-Antoine Gatier decided its next paint job should employ the “yellow-brown” hue used in 1907 and preferred by Gustave Eiffel. The painting work is currently in progress, but there’s also a parallel campaign to strip away all of the previous layers, which weigh a combined 350 tons. The work, entirely carried out by hand, will take years to complete.It was only supposed to be a pop-up.The space for the Eiffel Tower on the Champs de Mars was permitted to Gustave Eiffel as a 20-year concession, but even before that period was set to end in 1909 the monument’s future was in serious doubt. Indeed, after the 1889 world’s fair, the tower’s popularity and visitor numbers began to wane, and talk of pulling the whole thing down intensified. In 1903, various commissions mandated by the city of Paris resulted in split votes on whether to keep or destroy the giant structure. The uncertainty would reign for years.It saved France.At the base lie the remains of an installation that saved the Eiffel Tower from being torn down and may even have gone a long way toward saving France during World War I. But the average person can’t see them—they’re buried underneath the Champs de Mars gardens near the south pillar.There, a space now called “the bunker”—and still used for tower operations—contained early versions of wireless telegraphy equipment installed by Eiffel and the French military. Eiffel had a lifelong interest in science and decided early on to use the tower to carry out research in meteorology and aerodynamics. Then when pressure was mounting over the future of the monument, he agreed to fund military research into the emerging wireless communications field. In early tests carried out in an above-ground shack near the foot of the tower, a young officer was able to establish communications with forts in eastern France, then Tunisia and even Canada. A more permanent underground station was built in 1910, improving the tower’s chances of survival.The Eiffel Tower really proved its strategic importance four years later. In September 1914 the French used the communications system to intercept the German army’s messages, allowing France to block its advance in the Battle of the Marne. With that, Gustave Eiffel sealed his concession for another 70 years.It got taller in 2022.Ever since those early days experimenting with wireless communications, the Eiffel Tower has been a literal beacon. Today it’s used as a digital radio and TV emitter with 116 antennae. The most recent one was installed in 2022 by helicopter, raising the structure’s height to 330 meters (1,083 feet).The destination restaurant was part of Eiffel’s vision, but a perfect kitchen was not.When the Eiffel Tower opened, the first floor had ornately decorated restaurants serving French, Alsatian and Russian specialties and an Anglo-American bar, all part of Gustave Eiffel’s forward-looking vision to attract tourists. But cooking in the tower has never been straightforward.Look no further than the second-floor restaurant Jules Verne, which has been the tower’s buzziest place since it got its first Michelin star four decades ago. In 2017, French President Emmanuel Macron and his counterpart Donald Trump had a private dinner there with their wives. Earlier this year, it was one of just eight restaurants in France to earn two Michelin stars, and the Gault & Millau guidebook named its chef, Frédéric Anton, “Chef of the Year” for 2025. Yet Jules Verne operates under a number of constraints that no other Parisian restaurant would likely endure.For one thing, gas stoves—preferred by chefs for precise temperature control and even heat distribution—aren’t allowed for safety reasons. Supplies can only be transported to the kitchen via a service elevator and only in the early-morning hours, which means if a particularly festive group wants to order all the caviar in the house, the cooks can’t source more midshift.There are also weight limits on anything that stays in the kitchen and dining room permanently. What’s removed from the tower gets weighed, and whatever replaces it must have an equal or lesser tonnage. When catering giant Sodexo SA took over the Jules Verne concession in 2018 and decided to change the stove, for instance, the company was restricted to certain models—which also had to be broken down and brought up in pieces, as they didn’t fit in the lift.There’s a hidden floor that few can see.Visitors who pay careful attention while riding the elevator between the second and third floors can catch a glimpse of an intermediate platform. The lift hasn’t made regular stops there for tourists for more than four decades.The secret floor harks back to the tower’s earlier days, before technological advances allowed for a system to reach the very top in one go. In the first weeks after the tower was inaugurated on March 31, 1889, the only way up was via 1,710 stairs. But Eiffel soon obtained government permission to begin operating the tower’s five lifts, which would set records for their trajectory and load capacity. For the highest level, Eiffel had called upon a former engineering school classmate and inventor, Félix Léon Edoux, to devise a system that could carry guests the final 160 meters from the second to the third floor.With Edoux’s two-step system, guests would take one lift up to an intermediate platform, then disembark and transfer to another for the final stretch. It was clunky, inefficient and prone to breaking down in the winter, when the hydraulics sometimes froze. Yet it wasn’t replaced until 1983, when the current-day double-cabin electric elevators were installed.As for the now-defunct platform? It’s used as storage space, and elevators can stop there in an emergency. “It’s a sort of secret place that not many people get to see,” says Yeatman-Eiffel.Only two people are believed to have ever slept in the tower’s apartment, and Eiffel wasn’t one of them.Included in the €35.30 ($36.81) adult ticket price to visit the top of the Eiffel Tower is a glimpse at a tiny reconstructed version of Gustave Eiffel’s “apartment,” complete with wax renditions of the engineer, his daughter Claire, and Thomas Edison, who brought a phonograph during a visit.“Apartment” really just means “rooms” in this case. The space was comprised of three small offices, a reception area with a piano, a kitchenette and small bathroom. But Eiffel loved the view from up there, and between 1903 and 1912 it was a productive place for him to carry out meteorological readings and publish scientific papers; he also used it to welcome VIPs like Sarah Bernhardt, Buffalo Bill and a host of European royals. It was his way of promoting the tower, and himself as businessman. What he didn’t do was spend the night there. There wasn’t even a bed.“There are only two people who we can say with certainty slept there,” says Savin Yeatman-Eiffel, who has a photo of his grandparents at the top of the tower the morning after their wedding night in August 1935, glasses of Champagne in hand. They were definitely onto something: They were standing very close to where there’s now a Champagne bar.You can buy a piece of it.The tower’s metal frame weighs 7,300 tons and has 18,038 iron parts and 2.5 million rivets. But those numbers have fluctuated over the years, as renovations have resulted in various parts being removed or replaced. Tons of machinery and original Eiffel Tower cast iron, in fact, comprise an increasingly valuable treasure, held in a warehouse near Paris; their whereabouts are so tightly kept under wraps, even Yeatman-Eiffel has no idea where they might be.Much of that cache was taken off the tower in the early 1980s, during the same major renovation that replaced the elevator system between the second and third floors. In that process, an original circular staircase was removed and cut into 24 sections. One is on display on the first floor of the tower, and three are in French museums. The rest were sold at auction. In 2020 the No. 17 section that had been in a private collection in Canada sold for €253,500 at auction. At that rate, the remaining metal is likely a multimillion-dollar prize.The Olympics served as a reminder of that secret metal stash; some of it was used in the 5,084 bronze, silver and gold medals awarded to athletes. “We married the strongest symbol of the Games, the medal, with the ultimate symbol of Paris and France around the world, the Eiffel Tower,” said Tony Estanguet, head of the organizing committee.But anyone can buy a little piece of the tower for far less than a six-figure sum—at least for now. A limited series of 600 round-headed rivets made from tower iron removed during renovations are on sale at the visitors’ boutique for €525 each. You can even buy them online, no trip to Paris required.116561696