During the pandemic, the Aon Center fell to fourth on the list of Chicago’s tallest skyscrapers, with the completion of the Jeanne Gang-designed St. Regis Chicago condo and hotel tower, formerly known as Vista Tower. The 101-story skyscraper is 1,191 feet tall. The Aon Center is 1,136 feet tall.
Aon Center’s $185 million observatory is delayed again
