On May 6, 1889, the World's Fair opened in Paris, France. Thirty-two million visitors came from around the globe over the next six months. The star of the fair was the Eiffel Tower, a 1,000-foot iron structure designed by engineer Gustave Eiffel. At the time, it was the tallest thing humans had ever built. The fair celebrated the 100th anniversary of the French Revolution, and France wanted to show the world that it was a modern, powerful nation. Countries set up displays showing off their newest inventions, foods, and art. Visitors could ride elevators to the top of the tower and see all of Paris below. Not everyone loved the tower. A group of famous French artists and writers signed a letter calling it an "iron monstrosity" that ruined the skyline. They predicted it would be torn down after the fair. But the tower stayed, and people grew to love it. Today, the Eiffel Tower is the most visited paid monument in the world, attracting about seven million visitors each year. Paris itself is the most visited city in Europe, and the tower is its most recognizable landmark.