Eiffel Tower
The Eiffel Tower is the most famous landmark in France, and one of the most famous in the world. It was built in just two years (1887 to 1889) for the Paris World's Fair to celebrate the 100th anniversary of the French Revolution. At the time it was the tallest building in the world. It was meant to be torn down after 20 years. But over 130 years later, here it still is, attracting around 7 million visitors a year.
- CountryFranceIn the capital city, Paris
- Built1887 to 1889Took just 2 years and 2 months
- Height330 metresIncluding its 24-metre TV antenna
- Iron used7,300 tonnesIn 18,038 separate pieces
- Visitorsapprox. 7 million/yearThe most-visited paid monument on Earth
- DesignerGustave EiffelA French engineer famous for iron bridges
How tall is the Eiffel Tower?
The Eiffel Tower was the tallest building in the world from 1889 until 1930, when the Chrysler Building in New York overtook it. Today over 200 buildings are taller.
What is the Eiffel Tower?
The Eiffel Tower is a giant lattice (criss-crossed) tower of iron, standing on the Champ de Mars beside the river Seine in Paris. It was named after its designer, the engineer Gustave Eiffel. Today it works as a TV and radio antenna, a tourist attraction, and a national symbol of France.
How was it built?
Building the Eiffel Tower in just two years was an extraordinary engineering feat for its time. The 18,038 separate iron pieces were drawn up in workshops to a precision of within one tenth of a millimetre, then bolted together on site by a team of approx. 300 workers. The four legs all had to meet perfectly at the first platform, which would have been impossible if any piece had been even slightly wrong.
To stop the legs from sinking unevenly, Eiffel used hydraulic jacks built into the bases to fine-tune them as the tower went up. Just one worker died during construction, which was almost unheard of for a project this big at the time.
The Parisians who hated it
When it was being built, many people in Paris thought the tower was an ugly monstrosity. A group of 300 famous artists and writers (including the composer Charles Gounod and the writer Guy de Maupassant) signed a letter of protest calling it a "useless and monstrous Eiffel Tower" that would dishonour Paris. The story goes that Maupassant later started eating lunch in the tower's restaurant every day, because it was the only place in Paris from which you could not see the tower.
The tower in wartime
When the Nazi army occupied Paris in 1940, French resistance workers cut the lift cables of the Eiffel Tower so that German soldiers had to climb the 1,665 steps if they wanted to hoist a swastika flag. When Hitler visited Paris, he chose not to climb. Adolf Hitler is said to have ordered the tower destroyed near the end of the war, but his commander in Paris refused to carry out the order.
Deeper dive: Eiffel's engineering, the iron lattice and the Statue of Liberty connection
The mathematical curve of the Eiffel Tower's legs was carefully calculated by Eiffel's team to handle wind loads. Wind pressure increases dramatically with height, so the tower has to be much wider at the base than at the top to resist toppling. The legs curve outward in a shape that resembles an exponential decay, with the wind force decreasing with height matched by the structural mass above it. Modern engineering analysis has confirmed that the curve is close to optimal: the tower sways only around 6 to 7 cm in strong winds.
The lattice structure of the tower was a deliberate choice. Solid iron walls would have been heavier, more expensive, and (more importantly) far more vulnerable to wind. The criss-crossed iron struts let wind pass through with minimal resistance while still providing huge rigidity per kilogram of metal. The total weight of all the ironwork is approx. 7,300 tonnes, but if it were melted down and cast as a single block at the tower's base, the block would be only 6 cm thick.
Eiffel's engineering firm did more than just the tower. The same company designed the internal iron framework of the Statue of Liberty in New York, completed three years before the Eiffel Tower. Eiffel also designed dozens of large iron railway bridges across France, Portugal and Vietnam, including the Maria Pia Bridge in Porto, the Garabit Viaduct in southern France, and the Long Bien Bridge in Hanoi. He was a pioneer in the use of wrought iron and a careful calculator who designed his structures with significant safety margins, which is why so many of them are still standing more than 130 years later.
The Eiffel Tower's engineer also did the inside of the Statue of Liberty. The country is France.