After graduation from the College of Art and Manufacturing in 1855, Eiffel began to specialize in metal construction, especially bridges. He directed the erection of an iron bridge at Bordeaux in 1858, followed by several others, and designed the lofty, arched Gallery of Machines for the Paris Exhibition of 1867. In 1877 he bridged the Douro River at Oporto, Port., with a 525-foot (160-metre) steel arch, which he followed with an even greater arch of the same type, the 540-foot (162-metre) span Garabit viaduct over the Truyère River in southern France, for many years the highest bridge in the world, 400 feet (120 m) over the stream. He was one of the first engineers to employ compressed-air caissons in bridge building. He designed the movable dome of the observatory at Nice and the framework of the Statue of Liberty (Liberty, Statue of) in New York Harbor.

Eiffel startled the world with the construction of the Eiffel Tower (1887–89), which brought him the nickname “magician of iron.” It also directed his interest to problems of aerodynamics, and he used the tower for a number of experiments. At Auteuil, outside Paris, he built the first aerodynamic laboratory, where he continued to work throughout World War I; in 1921 he gave the laboratory to the state.