The Eiffel Tower is an iron lattice tower located in Paris that was designed by Gustave Eiffel and built in 1889 as the entrance to the 1889 World's Fair. It is the tallest structure in Paris and the most visited paid monument in the world, receiving over 7 million visitors in 2011. Maintenance of the tower includes applying 50-60 tonnes of paint every seven years to protect it from rust.