30 Rockefeller Plaza (officially the Comcast Building; formerly RCA Building and GE Building) is a skyscraper that forms the centerpiece of Rockefeller Center in the Midtown Manhattan neighborhood of New York City. Completed in 1933, the 66-story, 850 ft (260 m) building was designed in the Art Deco style by Raymond Hood, Rockefeller Center's lead architect. 30 Rockefeller Plaza was known for main tenant, the Radio Corporation of America (RCA) from its opening in 1933 until 1988 and then for General Electric until 2015, when it was renamed for its current owner, Comcast. The building also houses the headquarters and New York studios of television network NBC; the headquarters is sometimes called 30 Rock, a nickname that inspired an NBC sitcom of the same name. The tallest structure in Rockefeller Center, the building is the 28th tallest in New York City and the 60th tallest in the United States.
30 Rockefeller Plaza's massing consists of three parts: the main 66-story tower to the east, a windowless section at the center, and a 16-story annex to the west. Though the building was designed to conform with the 1916 Zoning Resolution, it rises mostly as a slab, with setbacks mostly for aesthetic value. The facade is made of limestone, with granite at the base, as well as about 6,000 windows separated by aluminum spandrels. In addition to its offices and studios, 30 Rockefeller Plaza contains the Rainbow Room restaurant and an observation deck called Top of the Rock. 30 Rockefeller Plaza also includes numerous artworks and formerly contained the mural Man at the Crossroads by Diego Rivera. The entire Rockefeller Center complex is a New York City designated landmark and a National Historic Landmark, and parts of 30 Rockefeller Plaza's interior are also New York City landmarks.
30 Rockefeller Plaza was developed as part of the construction of Rockefeller Center, and work on its superstructure started in March 1932. The first tenant moved into the building on April 22, 1933, but its official opening was delayed due to controversy over Man at the Crossroads. The Rainbow Room and the observation deck opened in the mid-1930s, and retail space was added to the ground floor in the 1950s. The building remained almost fully occupied through the 20th century. Since the late 1990s, NBC has owned most of the lower floors, while Tishman Speyer has operated the rest of the building. 30 Rockefeller Plaza was extensively renovated in 2014.