For 25 years, Chicago's 1,451 feet tall Willis Tower was the tallest building in the world. Constructed in 1974 and originally known as Sears Tower, Willis Tower dropped from first to third place in 1998 when it was surpassed in height by the twin Petronas Towers constructed in Kuala Lumpur. As of March 2011, Willis Tower is the eighth tallest building in the world. Most of the tower's 110 stories are filled by office space, although the lower stories contain retail stores, banking facilities and several restaurants.
Trump International Hotel and Tower, also located in Chicago, stands 1,362 feet tall and is the second tallest building in the U.S. Completed in 2009, it is unique among tall buildings because it is not predominantly occupied by office space. Instead, the tower's 92 stories hold 339 luxury hotel rooms alongside high-end restaurants, a ballroom, a conference center and a spa.
The 1,250 feet tall Empire State Building is perhaps the most famous component of New York City's skyline. Named after New York state's nickname as the Empire State, the 102-story tower was the world's tallest building for more than 40 years following its construction in 1931. The tower's interior comprises office space and two publicly accessible observatories on the 86th and 102nd floors. At night, lights on the tower's exterior change colors to reflect various local events and holidays. On St. Patrick's Day, for example, the lights glow bright green to reflect the holiday's official colors.
Bank of America Tower, located in midtown New York City, stretches 1,200 feet into the air and was completed in 2009. Its 55 stories are largely occupied by Bank of America itself. The tower was constructed with green principles in mind, and contains a rain collector on its roof, a wind turbine and a garden. It generates 70 percent of its own energy needs and was constructing primarily out of materials gathered from less than 500 miles away.
The Aon Center, formerly known as the Standard Oil Building and the Amoco Building, rises 1,136 feet into the Chicago skyline. The building contains 83 stories and was completed in 1972. The Aon Corporation, which acquired the tower in 1998, is the primary tenant.
