Boeing International Headquarters

The Boeing International Headquarters is a 36-floor skyscraper located in the Near West Side of Chicago. The building, at 100 North Riverside Plaza, is located on the west side of the Chicago River directly across from the downtown Loop. The building was designed with a structural system that uses steel trusses to support its suspended southwest corner in order to clear the Amtrak and Metra railroad tracks immediately beneath it. It won the Structural Engineers Association of Illinois' "Most Innovative" Design Award.
The building was originally constructed for the Morton Salt Company in 1990, but became largely vacant a decade later after the company was acquired and downsized. Boeing moved their corporate headquarters there in 2001 when they opted to leave Seattle for Chicago. Navteq moved their headquarters to the Boeing Building in 2007. It has also housed offices of Ameritech.

Wikipedia