The Willis Tower, originally and still commonly referred to as the Sears Tower, is a 110-story, 1,451-foot (442.3 m) skyscraper in the Loop community area of Chicago in Illinois, United States. Designed by architect Bruce Graham and engineer Fazlur Rahman Khan of Skidmore, Owings & Merrill (SOM), it opened in 1973 as the world's tallest building, a title that it held for nearly 25 years. It is the third-tallest building in the Western Hemisphere, as well as the 23rd-tallest in the world. Each year, more than 1.7 million people visit the Skydeck observation deck, the highest in the United States, making it one of Chicago's most popular tourist destinations.
Willis Tower as seen from Lake Michigan in April 2019
The Sears Tower (now Willis Tower) during its construction in 1973
The tower in 1978, after its completion
The tower at night in 2009
A storey or story, is any level part of a building with a floor that could be used by people. Plurals for the word are storeys (UK) and stories (US).
A large elevator panel in a North American high-rise omits several floors as well as designating three separate levels as penthouse floors.
An elevator control panel in an apartment building in Shanghai. Floors 4, 13 and 14 are missing.
Letter boxes of a residential building built in the 1970s in Hong Kong. The Chinese and English floor numberings use the traditional Chinese and the British systems, respectively, resulting in different numbers.
A Dover Custom Impulse Elevator control panel with floor numbering. In most buildings in the US and Canada with more than 12 floors, there is no floor numbered 13. The ☆ indicates the main entry floor.
