The Eiffel Tower is a pudellated iron structure originally designed by the civil engineers Maurice Koechlin and Émile Nouguier and built, after aesthetic redesign by Stephen Sauvestre, by the French civil engineer Alexandre Gustave Eiffel and his collaborators for the 1889 Universal Exhibition in Paris.

Located at the edge of the Champ de Mars on the banks of the Seine River, this Parisian monument, symbol of France and its capital, is the tallest structure in the city and the most visited entrance monument in the world, with 7.1 million tourists each year. With a height of 300 metres, later extended by an antenna to 324 metres, the Eiffel Tower was the tallest structure in the world for 41 years.

It was built in two years, two months and five days, and at the time generated some controversy among artists of the time, who saw it as an iron monster. After completing its function as part of the Universal Exhibitions of 1889 and 1900, it was used in French army tests with communication antennae, and today it serves, in addition to being a tourist attraction, as a radio and television broadcasting station. On 15 March 2022, the radio antenna was replaced with the help of a helicopter, raising it from 324 m to 330 m in total height.

Initially the subject of controversy for some, the Eiffel Tower served as a presentation for the Paris Universal Exhibition of 1889, and has welcomed more than 250 million visitors11 since it was inaugurated. Its exceptional size and instantly recognisable silhouette made the tower an emblem of Paris.

Conceived in the imagination of Maurice Koechlin and Émile Nouguier, head of the design office and head of the methods office respectively at Eiffel & Co, it was intended to be the "nail (centre of attention) of the 1889 exhibition to be held in Paris", which would also commemorate the centenary of the French Revolution. The first plan of the tower was drawn in June 1884. Stephen Sauvestre, the chief architect of the company's projects, was commissioned to improve its aesthetics.

On 1 May 1886, the Minister of Trade and Industry, Édouard Lockroy, an enthusiastic supporter of the project, signed a decree declaring open "support for the Universal Exhibition of 1889". Gustave Eiffel won this financial support and signed an agreement on 8 January 1887 setting the terms for the construction of the building.

Built in two years, two months and five days (from 1887 to 1889) by 250 workers, it was officially inaugurated on 31 March 1889. Resisting the continuous effect of corrosion on its metal structure, the Eiffel Tower did not really enjoy massive and constant success until the 1960s, with the development of international tourism. It now welcomes more than six million visitors each year.