Eiffel Tower
By this time, the city had learned that the tower could be used to help with communications. There was also a metrology lab that had been installed for studies on everything from gravity to electricity. The military used the tower as a wireless telegraph transmitter for communication during battle. The tower was used in the capture of the spy "Mata Hari" during World War I after a message was intercepted. Today, it is used to send radio and television signals to the capital city of Paris and beyond. After people learned about the many benefits the tower provided, no one wanted it to be taken apart.