Eiffel Tower Visit under the tower in photo
The Eiffel Tower stands on four lattice-girder piers that taper inward and join to form a single large vertical tower. As they curve inward, the piers are connected to each other by networks of girders at two levels that afford viewing platforms for tourists. By contrast, the four semicircular arches at the tower's base are purely aesthetic elements that serve no structural function. Because of their unique shape, which was dictated partly by engineering considerations but also partly by Eiffel's artistic sense, the piers required elevators to ascend on a curve; the glass-cage machines designed by the Otis Elevator Company of the United States became one of the principal features of the building, helping establish it as one of the world's premier tourist attractions.
The tower itself is 300 metres (984 feet) high. It rests on a base that is 5 metres (17 feet) high, and a television antenna atop the tower gives it a total elevation of 324 metres (1,063 feet). The Eiffel Tower was the tallest man-made structure in the world until the topping off of the Chrysler Building in New York City in 1929.