Aon Center (Chicago) Aon Center (Chicago) The Aon Center (200 East Randolph Street, formerly Amoco Building) is a modern supertall skyscraper in the Chicago Loop, Chicago, Illinois, United States, designed by architect firms Edward Durell Stone and The Perkins and Will partnership, and completed in 1974 as the Standard Oil Building. With 83 floors and a height of 1,136 feet (346 m), it is the third tallest building in Chicago, surpassed in height by the Willis Tower, and the Trump International Hotel and Tower. The building is managed by Jones Lang LaSalle, which is also headquartered in the building. Aon Center formerly had
Vista Tower (Chicago) Vista Tower (Chicago) Construction started in August 2016 with expected completion in 2020. Upon completion, it will become the city's third-tallest building at . Designed by a team led by architect Jeanne Gang, Vista will supplant the nearby Aqua skyscraper (also designed by a team led by Jean Gang) as the tallest structure in the world designed by a woman. This will make Chicago home to the two tallest structures designed by a woman. Vista Tower is a joint project of Magellan Development Group and Wanda Group. The original estimated cost of construction was $900 million. The building will have