Tower Bridge (London)

It is a unique Victorian-era "bascule" (seesaw) bridge that was originally chocolate brown, not its current red, white, and blue. Until 1976, the bascules were operated by coal-burning steam engines, which were later replaced by electric motors. Fun fact: On December 30, 1952, driver Albert Gunter had to accelerate bus 78 to jump a 3-foot gap when the bridge began rising unexpectedly, landing safely.