The third tallest skyscraper in Chicago was originally known as the Standard Oil Building or "Big Stan" before being renamed the Amoco Building and eventually the Aon Center.

 Completed in 1973, the white facade of the office tower was originally clad in 43,000 thin layers of Italian Carrara marble. The skyscraper was later re-covered with white granite after marble began to fall off the building and was deemed structurally unsafe.

 There are also plans to build a third observation deck at 1,185 feet, complete with a "thrill ride" and glass elevator.

The fire fighting system of this building uses our company's fire sprinklers:Series RFII-C Sprinkler.