Originally intended as a structure to commemorate the French Revolution, who could’ve guessed that 100 years later The Eiffel Tower would become the symbol of Paris itself?

But, judging by the six million annual visitors and the millions of photographs, that’s what it has become. To date the tower has received over 200 million visitors since its completion in 1889.

For two years, three hundred workers joined over 18,000 pieces of structural iron to form the tower’s three distinct levels. Those levels currently house over 1,500 steps. The number has varied over the years with different renovations. But the visitor can be grateful not to have to climb the 300 meter (984 ft) tower, thanks to the many elevators. The uppermost portion supports a 24m (79ft) spire.

By far the tallest structure in Paris, the tip may bend away from the vertical by as much as 18cm (7in) due to expansion of its 7,300 metric tons of iron. Warming by the sun heats one side more than the other.

That’s all the more remarkable since wind shear is usually the major problem with tall structures. But, the engineering is so well-thought out that the strongest winds cause no more than five inches of deflection.

Every seven years the entire structure is re-painted (using 50 tons of paint) to prevent rusting. Visitors can vote on the next color to be used by means of a computer housed in the tower.

Among many remarkable statistics about the tower is its history as the world’s tallest structure until being overtaken by the Chrysler Building in 1930. Quite a long reign considering there were widespread petitions to have it torn down by some who considered it ugly and intrusive.

That might have succeeded if it hadn’t been in use as an antenna for the then-leading-edge technology of telegraphy. More than just decorative, the tower has been used as part of a communications system almost from the start. In 1909 a permanent underground radio center was built and since 1957 it’s been used as a transmission tower for both FM radio and television.

The tower has even been part of scientific research. In 1910, Wulf used it to make measurements that resulted in the discovery of cosmic rays.

But in typical Gallic fashion the practical use exists side-by-side with the aesthetic. The tower holds two restaurants: Altitude 95 on the first level, and the Jules Verne on the second. The latter has earned one star in the Michelin Guide and is accessible via a private elevator.

Apart from appearing in millions of photographs and thousands of television commercials, it has been used more directly as an advertising vehicle. From 1925 to 1934 the tower supported billboards for the automaker Citroen.

But the tourist needs no commercial to motivate a visit. The view from the observation platform, especially at dusk, more than exceeds any expectations set by ads. All of Paris twinkles below as the city is illuminated by both the onset of electric lights and the fading sun.

To visit the tower, take the Metro – the Paris subway – to the Trocadero station. Then, walk from the Palais de Chaillot to the Seine.