The Eiffel Tower was built as a temporary structure for what event?

A radio antenna saved the Eiffel Tower from being torn down. From the beginning, the Eiffel Tower was only supposed to remain up 20 years after the 1889 World's Fair —it was supposed to be torn down afterward. Eiffel was very aware of this and cleverly ensured the Tower’s existence by enhancing it with a radio antenna and a wireless telegraph transmitter. The Tower began transmitting radio signals locally at the turn of the 20th century, acting as a military radio post in 1903 and later helping France to defend itself from enemy attacks during the First World War. The radio’s usefulness secured the tower a 70-year extension on its lease and by the time it was up in 1980, the monument’s iconic silhouette had become an irrevocable part of Paris’ skyline.

Source: Travel and Leisure