When three Columbia professors submitted their design for the new Boston City Hall little did they know their brutalist based concept would end up producing one of the most controversial and unique buildings to ever be built in the U.S. The 9 story building is almost completely made of poured in place or pre-cast concrete components. The most notable features of the building are the large cantilevered floors and the repeated use of concrete vertical louver systems. The ability to pass through the building's courtyard was a greatly heralded feature at the time of it's completion but due to security concerns the access to the courtyard has been heavily restricted for most of the buildings life. In 1969 Kallmann, McKinnell and Knowles was awarded with an AIA Award for Architecture as well as the Harleston Parker Medal from the City of Boston for the building's design. The surrounding plaza known as government center was designed by I.M. Pei and has been regarded as one of the worst public spaces in existence by many planners and city planning organizations including the Project for Public Places. Model created by Nathan Kohrmann.