Info from Wikipedia
Late Night with Conan O'Brien is an American late-night talk show hosted by Conan O'Brien. NBC aired 2,725 episodes from September 13, 1993, to February 20, 2009.
Late Night was a production of Lorne Michaels's Broadway Video (and, since 2003, O'Brien's Conaco). It was taped in Studio 6A in the GE Building at 30 Rockefeller Plaza in New York City.