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
Library Tower (Chicago) Library Tower (Chicago) Library Tower Chicago is located on 520 S. State Street, Chicago, Illinois, which is the block directly south of the main branch of the Chicago Public Library in the Loop community area. Currently (4/2009) the building has 184 Units. 52 units have been sold and closed. Another 36 are under contract. Apparently, the building was mostly sold unit the economy forced investors to pull out of the building, leaving it largely unsold. Units have been on sale since 2005, with closing first occurring in 2008. There has been substantial price drops from being on the market (1