The Eiffel Tower

The Eiffel Tower (French: La Tour Eiffel) is an iron tower built on the Champ de Mars beside the River Seine in Paris, France. It is one of the tallest structures in Paris and possibly one of the most recognized monuments in the world. Named after its designer, engineer Gustave Eiffel, it is the most visited monument in the world; 6,428,441 people visited the tower in 2005 and more than 200,000,000 since its construction. Including the 24 m (78.7 ft) antenna, the structure is 324 m (1,063 ft) high (since 2000), which is equivalent to about 81 levels in a conventional building.
In 1902, it was struck by lightning, which meant that 100 metres of the top had to be reconstructed and the lights illuminating the tower had to be replaced, as they were damaged by the high energy of the lightning.
At the time of its construction in 1887, the tower replaced the Washington Monument as the world's tallest structure, a title it retained until 1930, when New York City's Chrysler Building (319 m/1,046.58 ft tall) was completed (today, the Eiffel Tower is taller than the Chrysler Building). The tower is now the fifth-tallest structure in France. The Eiffel Tower is the tallest structure in Paris, with the second-tallest being the Tour Montparnasse (210 m/689 ft), although that will soon be surpassed by Tour AXA (225.11 m/738.5 ft).
The structure of the Eiffel Tower weighs 7,300 tons. There are 1,665 steps (360 to the first level, another 359 to the second). It is not possible for the public to reach the summit via the stairs, lifts are required beyond the second platform. Lift tickets may be purchased at the base or either platform. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18cm, due to thermal expansion of the metal on the side facing the sun. The tower also sways 6-7cm in the wind. Maintenance of the tower includes applying 50/60 tons of three graded tones of paint every seven years to protect it from rust. On occasion, the color of the paint is changed — the tower is currently painted a shade of brownish-gray. However, the tower is actually painted three different colors in order to make it look the same color. The colors change from dark to light from top to bottom, but it looks the same because of the background (the sky being light and the ground being dark).
On the first floor, there are interactive consoles hosting a poll for the color to use for a future session of painting. The co-architects of the Eiffel Tower are Emile Naugier, Maurice Koechlin and Stephen Sauvestre.

en.wikipedia.org/wiki/Eiffel_tower