The Eiffel Tower (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, making it the most visited paid monument in the world. When the tower was completed in 1889 it was the world's tallest tower — a title it retained until 1930 when New York City's Chrysler Building was completed. The structure was built between 1887 and 1889 as the entrance arch for the Exposition Universelle, a World's Fair marking the centennial celebration of the French Revolution. Eiffel originally planned to build the tower in Barcelona, for the Universal Exposition of 1888, but those responsible at the Barcelona city hall thought it was a strange and expensive construction, which did not fit into the design of the city. After the refusal of the Consistory of Barcelona, Eiffel submitted his draft to those responsible for the Universal Exhibition in Paris, where he would build his tower a year later, in 1889. The tower was inaugurated on 31 March 1889, and opened on 6 May. Three hundred workers joined together 18,038 pieces of puddled iron (a very pure form of structural iron), using two and a half million rivets, in a structural design by Maurice Koechlin. The risk of accident was great, for unlike modern skyscrapers the tower is an open frame without any intermediate floors except the two platforms. However, because Eiffel took safety precautions, including the use of movable stagings, guard-rails and screens, only one man died.