More than 1.7 million people make their way to Willis Tower's Skydeck Chicago each year, and it's easy to see why. Occupying the 103rd floor – that's nine floors higher than 360 CHICAGO – of ...

(Bloomberg) -- Ken Griffin’s Citadel is departing the iconic Chicago tower that once served as its headquarters, cutting one of its last remaining ties to the city. The financial conglomerate is ...