The Eiffel Tower sways in the wind, by design

The Eiffel Tower, completed in 1889, isn't rigidly fixed; its open iron lattice framework is engineered to flex with the wind. This ingenious design, by Gustave Eiffel, uses 18,038 riveted iron pieces to allow wind to pass through, reducing pressure. This flexibility prevents the tower from toppling, a breakthrough for 19th-century architecture that challenged solid, immovable designs.