Rockefeller Center celebrates a milestone this month, marking its 85th anniversary since opening its doors in May 1933. An architectural feat that prevailed despite the Great Depression, employing over 40,000 people during those lean years, it's a gem of urban design from its centerpiece tower (the RCA Building, now known as 30 Rock) to the Plaza, Promenade and Rink Level. According to writer Brendan Gill, "Rockefeller Center amounts to an extended family of buildings, none of which, though they grow older, appears to grow old."

John D. Rockefeller Jr. initially planned the development as the new home for the Metropolitan Opera, but after the stock market crash of 1929, the Opera bowed out of the project and Rockefeller funded it himself, making it one of the most ambitious private construction projects ever undertaken. (Rockefeller's fortune was amassed by his father, John D. Sr., who co-founded Standard Oil and became the richest person in America.) The design took shape with the influence of figures including architect Raymond Hood, Radio City Music Hall designer Donald Deskey, and Abby Aldrich Rockefeller, founder of MoMA and wife of John D. Jr., who advocated for Art Deco modernism and helped the Center become home to over 100 works of public art. The forward-looking planners envisioned Rockefeller Center as a grand public space, a commercial center and a media hub, and it still fulfills all of those roles, from its restaurants, shops and businesses to the world-famous skating rink and Christmas Tree (a tradition started by Rock Center's workers in 1931), to NBC Studios, where fans flock for tours and tapings.

Click through the slideshow above to see the construction of the Center, including images with the Empire State Building and St. Patrick's Cathedral in the backdrop, and photos showing some of the earliest visitors to the observation deck (later relaunched as Top of the Rock), as well as the first-class team of guides who staffed it. Learn about the buildings' construction workers, and take a tour of Rockefeller Center to discover more of its history, art and architecture.