The Eiffel Tower was built by Gustave Eiffel for the 1889 Exposition Universelle, which was to celebrate the 100th year anniversary of the French Revolution. Its construction in 2 years, 2 months and 5 days was a veritable technical and architectural achievement. "Utopia achieved", a symbol of technological prowess, at the end of the 19th Century it was a demonstration of French engineering, and a defining moment of the industrial era. As France’s symbol in the world, and the showcase of Paris, today it welcomes almost 7 million visitors a year, making it the most visited monument that you have to pay for in the world.