Gustave Eiffel constructed the Eiffel Tower for the Exposition Universelle in 1889, which commemorated the 100th anniversary of the French Revolution. Its construction in 2 years, 2 months, and 5 days was an impressive feat of engineering and architecture. At the end of the 19th century, “Utopia achieved,” a symbol of technological superiority, was a feat of French engineering and a turning point in the development of the industrial age. Today, it receives about 7 million visitors a year, making it the most visited paid-entry monument in the world and serving as both the symbol of France and the showcase for Paris.

One of the most iconic structures in the world, the Eiffel Tower, also known as La Tour Eiffel, represents the romanticism and creativity of the City of Lights.

The Tower was initially intended to celebrate the centennial of the French Revolution and display France’s cutting-edge mechanical skill on a global scale as the focal point of the Paris World’s Fair in 1889.

And it did just that. It was regarded as a miracle of accuracy and speed when it was finished since it was constructed in a record amount of time—two years, two months, and five days. With 7,300 tons of iron and 2.5 million rivets, Gustave Eiffel’s civil engineering company created a structure that triumphed over the Champs de Mars and welcomed two million visitors while the fair was in session.

China, Las Vegas, Prague, and of course Paris, Texas have all copied the Tower’s now-famous silhouette. A “Protest against the Tower of Monsieur Eiffel” signed by people like Guy de Maupassant, Alexandre Dumas Junior, and other well-known artists was printed in a Parisian newspaper prior to the Tower’s completion. The design, however, was not without its critics. They claimed it would resemble “a gigantic black factory chimney, its barbarous mass overwhelming and humiliating all our monuments and belittling our works of architecture, which will just disappear before this stupefying folly.”

Fortunately, the Tower did see the light of day and has endured the test of time in defiance of its opponents. One of the most popular tourist attractions in the world, the Eiffel Tower has hosted more than 300 million visitors since it first opened its doors to almost 7 million visitors annually. With the addition of lighting, new paint, and other installations that came and went, it has altered throughout time.

And this landmark still has more to it than first appears. There are still mysteries to be revealed about the Iron Lady despite the staggering number of people who have climbed it.