The CBS Building, also known as Black Rock, is the headquarters of the CBS broadcasting network at 51 West 52nd Street in the Midtown Manhattan neighborhood of New York City. The 38-story, 491-foot-tall (150 m) building, the only skyscraper designed by Eero Saarinen, was constructed from 1961 to 1964. The interior spaces and furnishings were designed by Saarinen and Florence Knoll Bassett. The building previously served as the headquarters of CBS Records (now Sony Music Entertainment) until the early 1990s.
The building is on Sixth Avenue (Avenue of the Americas) between 52nd and 53rd Streets, although its main entrances are on the side streets. The "Black Rock" nickname is derived from the design of its facade, which consists of angled dark-gray granite piers alternating with dark-tinted glass. The facade was designed to make the building appear as a continuous slab. Inside, the building has a gross floor area of approximately 800,000 square feet (74,000 m2). The building's superstructure is made of reinforced concrete, and steel beams are only used below ground. Saarinen referred to the building as the "simplest skyscraper statement in New York".
Construction started in 1961 and, despite Saarinen's death shortly afterward, the design was finalized in 1962. The first employees moved into the building in late 1964 and it was completed the following year. The building initially served as the headquarters of CBS, which occupied all the above-ground space until the early 1990s, when CBS started leasing some stories to other tenants. The New York City Landmarks Preservation Commission designated the CBS Building as a city landmark in 1997. CBS attempted to sell the building twice between 1998 and 2001, and ViacomCBS again attempted to sell it in early 2020. ViacomCBS announced it would sell the building for $760 million to Harbor Group International in August 2021.