The design, by Adrian D. Smith of Skidmore, Owings & Merrill, is considered one of the finest reproductions of the Art Deco style. It was inspired by 30 Rockefeller Plaza in New York City, which is NBC's global headquarters. The tower is further enhanced by the use of limestone piers and recessed tinted glass with granite spandrels. The building takes additional cues from the nearby landmark Tribune Tower with the use of flying buttresses. A 130 ft (40 m) broadcast tower and spire tops the skyscraper. WMAQ and WSNS have STL and satellite facilities on the roof; the STLs link to WMAQ and WSNS's transmitter facilities atop the Willis Tower. WMAQ radio/WSCR studios and STL were located in the building until 2006 when they relocated to Two Prudential Plaza.