Architecture of Chicago a new structural system of framed tubes in skyscraper design and construction. The first building to apply the tube-frame construction was the DeWitt-Chestnut Apartment Building which Khan designed and was completed in Chicago by 1966. This laid the foundations for the tube structures of many other later skyscrapers, including his own constructions of the John Hancock Center and Willis Tower (then named the Sears Tower) in Chicago and can be seen in the construction of the World Trade Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s. Willis Tower would be the world's tallest building
Chicago Water Tower Louisville Water Tower in Louisville, Kentucky. The Chicago Water Tower now serves as a Chicago Office of Tourism art gallery known as the City Gallery in the Historic Water Tower. It features the work of local photographers and artists, and filmmakers. The tower, built in 1869 by architect William W. Boyington from yellowing Lemont limestone, is 182 feet (55 m) tall. Inside was a 138-foot (42 m) high standpipe to hold water. In addition to being used for firefighting, the pressure in the pipe could be regulated to control water surges in the area. Together with the adjacent Chicago Avenue