The Eiffel Tower (French: Tour Eiffel) is an iron tower built on the Champ de Mars beside the Seine River in Paris. The tower has become a global icon of France and is one of the most recognizable structures in the world. Named after its designer, engineer Gustave Eiffel, the Eiffel Tower is the tallest building in Paris. More than 200,000,000 people have visited the tower since its construction in 1889. At the time the tower was built many people were shocked by its daring shape. The shape of the tower was determined by mathematical calculation involving wind resistance.