432 Park Avenue in New York City[14] Bally's to Bellagio, Bally's to Caesars Palace, and Treasure Island to The Venetian Pedestrian Bridges in Las Vegas Bloomberg Tower/731 Lexington in New York City Citigroup Center in New York City — Designed by William LeMessurier and completed in 1977, it was one of the first skyscrapers to use a tuned mass damper to reduce sway.[15] Uses a concrete version. Comcast Center in Philadelphia — Contains the largest Tuned Liquid Column Damper (TLCD) in the world at 1,300 tons.[16] Comcast Technology Center in Philadelphia — A set of five tuned dampers containing 125,000 gallons of water—about 500 tons—are located on the 57th floor between the hotel's rooms and lobby.[17] Grand Canyon Skywalk, Arizona The Hancock Tower in Boston — A tuned mass damper was added to it after it was built making it the first building to use a tuned mass damper. One Madison in New York City[18] One Rincon Hill South Tower, San Francisco — First building in California to have a liquid tuned mass damper Park Tower in Chicago — The first building in the United States to be designed with a tuned mass damper from the outset.