When Paris decided to stage the Universal Exposition of 1889, Gustave Eiffel built his famous tower on land granted to him by the city. Believe it or not, it was designed to be a temporary structure, something to be torn down after the exposition was over. Eiffel couldn’t let this happen so he started looking for a way to prove the usefulness of his monument.
On November 5, 1898, the Eiffel Tower was used in a demonstration of radio when a signal was sent from the top of the structure to another building about five kilometers away. It worked. Within a few years, the Eiffel Tower was being used for radio transmission experiments. In 1908, a signal sent from the top of the tower was received 5,000 kilometers away. That was enough to prove its strategic worth and the tower was saved.
Today, the Eiffel is still the site of various radio antennas.