Rockefeller Center is a large complex of 19 commercial buildings located on 22 acres of land between 48th and 51st Streets in Midtown Manhattan, New York City, New York. It was built from 1930 to 1939 under John D. Rockefeller Jr., who originally envisioned the site as the grounds for a new Metropolitan Opera building; after the Met could not afford to move to the new building, it was converted into commercial space. It includes the Radio City Music Hall, NBC Studios, and several other buildings, and the magnificent Great Depression-era building project became a National Historic Landmark in 1987. Since December 1933, the center has been home to an annually-lit Christmas tree.