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
Tower Petroleum Building Tower Petroleum Building The Tower Petroleum Building (also known as The Tower Building) is a historic Art Deco Skyscraper located at 1907 Elm Street in the City Center District of Downtown Dallas. The tower, a contributing property in the Dallas Downtown Historic District and the Harwood Street Historic District, features Zig-zag Moderne styling and was designed by architect Mark Lemmon. The Tower Petroleum Building features Zig-zag Moderne motifs, one of the few buildings left in Downtown Dallas which features such designs. The building's facade is clad in limestone and has green spandrels panels between the windows. The upper floors of