Citigroup Centrer (formally Citicorp Center) , New York
"Some buildings already use advanced wind-compensating dampers. The Citicorp Center in New York, for example, uses a tuned mass damper. In this complex system, oil hydraulic systems push a 400-ton concrete weight back and forth on one of the top floors, shifting the weight of the entire building from side to side. A sophisticated computer system carefully monitors how the wind is shifting the building and moves the weight accordingly. Some similar systems shift the building's weight based on the movement of giant pendulums."