The Eiffel Tower was due to be scrapped in 1909.
Built from 28 January 1887 to 31 March 1889, the 300-metre tower was only a World's Fair attraction, scheduled for demolition after 20 years. Radio telegraphy saved it: as an antenna mast it was too useful to lose. In summer sun the top leans up to 18 centimetres away from the light.
Useful: A second use can save a structure whose first purpose has expired.
Source: en.wikipedia.org