The Rookery is considered to be Chicago's oldest standing skyscraper. Its structural engineering, interior light court and glass topped lobby make it one of Chicago's most important buildings.
The Rookery's lobby is one of its most important architectural features. It's original John Root design was remodeled in 1905 by Frank Lloyd Wright. Flooded with natural light via its glass atrium ceiling, it was cutting edge architecture at the time it was built in 1885, and is in and of itself, a Chicago landmark.
A favorite feature of the building is the interior staircase. Winding from top to bottom, it wants to be climbed. Today's fire code would not allow the construction of an open stair like this making it more unique and aesthetically pleasing as time passes.