The Blue Cross Blue Shield Tower (BCBS) is located on the north end of Grant Park along E. Randolph Street at the NE corner of Randolph and Columbus Drive. The building is located next to the Aon Center and original plans hoped to connect the two buildings via an underground pedway but the plans never came to fruition.
Architect James Goettsch of Goettsch Partners designed the building. The 33-story first phase was completed in 1997 under the firm name of Lohan Associates (now Goettsch Partners). The 24-story second phase started in 2007 and was completed in 2010.
BCBS was originally designed to allow for many more floors to be built later as market conditions warrant and indeed in the center of the building you can see a large open space where more elevators can be inserted into the building to accommodate additional floors.
The building and the large expanse of windows facing Grant Park are often used to spell out words to commemorate or celebrate events and happenings in Chicago.