Iron, and lots of it

Stolen...

The Eiffel Tower (French: Tour Eiffel, [tuʀ ɛfɛl]) is a 19th century iron lattice tower located on the Champ de Mars in Paris that has become both a global icon of France and one of the most recognizable structures in the world. The Eiffel Tower, which is the tallest building in Paris,[1] is the single most visited paid monument in the world; millions of people ascend it every year. Named after its designer, engineer Gustave Eiffel, the tower was built as the entrance arch for the 1889 World's Fair. The tower stands at 324 m (1,063 ft) tall, about the same height as an 81-story building. It was the tallest structure in the world from its completion until 1930, when it was eclipsed by the Chrysler Building in New York City. Not including broadcast antennas, it is the second-tallest structure in France, behind the Millau Viaduct, completed in 2004. And while the Eiffel Tower is a steel structure, and weighs approximately 10,000 tonnes, it actually has a relatively low density, weighing less than a cylinder of air occupying the same dimensions as the tower. The tower has three levels for visitors. Tickets can be purchased to ascend either on stairs or lifts to the first and second levels. The walk to the first level is over 300 steps, as is the walk from the first to the second level. The third and highest level is only accessible by lift. Both the first and second levels feature restaurants. The tower has become the most prominent symbol of both Paris and France. The tower is a featured part of the backdrop in literally scores of movies that take place in Paris. Its iconic status is so established that it even serves as a symbol for the entire nation of France, such as when it was used as the logo for the French bid to host the 1992 Summer Olympics.