what is the name of the old sears tower in chicago
Willis Tower The Willis Tower, built as and still commonly referred to as the Sears Tower, is a 110-story,[4] 1,450-foot (442.1 m) skyscraper in Chicago, Illinois.[3] At completion in 1973, it surpassed the World Trade Center towers in New York to become the tallest building in the world, a title it held for nearly 25 years; it remained the tallest building in the Western Hemisphere until the completion of a new building at the World Trade Center site in 2014. The building is considered a seminal achievement for its designer Fazlur Rahman Khan.[5] The Willis Tower is the second-tallest building in the United States and the Western hemisphere – and the 16th-tallest in the world. More than one million people visit its observation deck each year, making it one of Chicago's most-popular tourist destinations. The structure was renamed in 2009 by the Willis Group as part of its lease on a portion of the tower's space.
Monadnock Building The Monadnock belongs to the Printing House Row District, a National Historic Landmark which includes the Manhattan Building, the Old Colony Building, and the Fisher Building, some of Chicago's seminal early skyscrapers.[96] The Manhattan Building, built by William LeBaron Jenney in 1890, was the first building in Chicago with a complete steel skeleton or "Chicago" construction, an innovation Jenney had introduced in the Home Insurance Building in 1884.[97] The first 16-story building in America, at the time it was "regarded with awe and fear".[98] Jenney's masterpiece, the Manhattan was considered a technical triumph in construction.[99] The 17-story Old Colony, built by Holabird & Roche in 1894, was considered one of the structural masterpieces of its time for its revolutionary portal form of bracing.[100] It is the only survivor of a group of Chicago school buildings with rounded corner bays.[101] The Fisher Building, built by Burnham in 1894, was an engineering miracleâ€”the first tall commercial building to be built almost entirely without bricks. Its steel frame and thin terracotta curtain wall allowed two-thirds of the surface to be covered with glass.[102]