"The building was designed principally by Gordon Bunshaft, and completed in 1974.[3] [4] The building was commissioned by the W.R. Grace Company, and was also used by the Deloitte & Touche, LLP formerly Deloitte Haskins & Sells. However, today it is inhabited by several other organizations, most notably AOL Time Warner and Limited Brands.
The building is located at 1114 Avenue of the Americas (also known as Sixth Avenue), but the main entrance is on 42nd Street, between 5th and 6th...One of the notable aesthetic attributes of the building is the concave vertical slope of its north and south facades, on 42nd and 43rd Street. This is similar to another of Bunshaft's creations, the Solow Building, which is no coincidence, as he had used the initial, rejected façade design for that building in his design for the Grace Building.[3] The exterior of the building is covered in white travertine, which forms a contrast against the black windows and makes the building appear brighter than those surrounding it." Wikipedia