The Eiffel Tower 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.
Maintenance of the tower includes applying 50 to 60 tonnes of paint every seven years to protect it from rust. In order to maintain a uniform appearance to an observer on the ground, three separate colors of paint are used on the tower, with the darkest on the bottom and the lightest at the top.
You may read more about the Eiffel Tower here.