The Aon Center is a modern skyscraper in the Chicago Loop

Chicago Loop

The Loop or Chicago Loop is one of 77 officially designated Chicago community areas located in the City of Chicago, Illinois. It is the historic commercial center of downtown Chicago...

, Chicago

Chicago

Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

, Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, designed by architect firms Edward Durell Stone

Edward Durell Stone

Edward Durell Stone was a twentieth century American architect who worked primarily in the Modernist style.-Early life:...

 and The Perkins and Will

Perkins and Will

Perkins+Will was founded in Chicago in 1935 by and ., on the belief that design has the power to transform lives and enhance society...

 partnership, and completed in 1973 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

Trump International Hotel and Tower (Chicago)

The Trump International Hotel and Tower, also known as Trump Tower Chicago and locally as the Trump Tower, is a skyscraper condo-hotel in downtown Chicago, Illinois. The building, named after real estate developer Donald Trump, was designed by architect Adrian Smith of Skidmore, Owings and Merrill...

. The building is managed by Jones Lang LaSalle

Jones Lang LaSalle

Jones Lang LaSalle, Inc. is a multinational financial and professional services company specializing in real estate. Global headquarters are located in Chicago, with an operational remit covering the Americas regional market...

. Aon has the headquarters of the Aon Corporation, and it formerly had the headquarters of Amoco

Amoco

Amoco Corporation, originally Standard Oil Company , was a global chemical and oil company, founded in 1889 around a refinery located in Whiting, Indiana, United States....

.