The tuned mass damper used in Taiwan’s Taipei 101 tower represents an engineering feat that is so impressive the designers decided to make it publicly visible for all to see. Taipei 101’s 730-ton tuned mass damper may represent an extreme, but its purpose is the same as much smaller dampers that may be used in an office building or mall: to mitigate vibrations or sway that may otherwise alarm or cause discomfort to building occupants.