Willis Tower

The Willis Tower was formerly the Sears Tower. Sears designed the building in the 1970s and has owned it since its completion. Sears sold the building in 1994, and Sears' name expired in 2003. The building's name was changed to Willis Tower in 2009 when London-based insurance brokerage Willis Group Holdings leased part of the building and acquired the rights to the building's name.

The Willis Tower has a roof and construction height of 1,450 feet (442 m), with two antennas at the top of the tower, and the western antenna increases the tower's total height to 527 m.After its completion in 1973, the Willis Tower was the tallest building in the world for 25 years, until 1998 when Kuala Lumpur's Petronas Towers surpassed its construction height. The Petronas Tower is much lower than the Willis Tower.

Standard height: 1451 ft / 442m

Floor count: 108

Year built: 1974

Observation Deck: 1352 ft / 412m

Uses: Office, Observation

City: Chicago