This 19 unit Art-Deco complex is one of New York’s most popular tourist destinations. Every year, it hosts the largest Christmas tree in the country, films a handful of national television’s most popular primetime talkshows as well as the 40 year-old ‘Saturday Night Live,’ and is probably the only New York landmark with a show, the Tina Fey creation ’30 Rock,’ named after its centerpiece, the GE Building. Rockefeller Center is one of the city’s most recognizable landmarks. It draws millions at all times of the year and exemplifies the crossroads of entertainment, corporate America, retail, and tourism, that is the Big Apple. It was completed in 1939 and named for John D. Rockefeller Jr., the son of the Standard Oil Founder John D. Rockefeller Sr. Rockefeller Center is a high traffic Manhattan destination, and has its fair share of secrets intwining it firmly with the city’s history and character. Here are 10 that we found the most eye-catching:

10. It’s the World’s Largest Privately Owned Complex

When John D. Rockefeller, Jr. planned Rockefeller Center in the early twentieth century, he meant for it to be “the grandest plaza in all of New York.” He leased the area in Midtown Manhattan that would become his namesake office complex from Columbia University in 1928, hoping to strike a deal with the Metropolitan Opera and built a newer, grander opera house.

In 1929, the stock market crash forced the Met to back out, and Rockefeller, deciding to go ahead with the purchase anyway, became the sole financier of the large plot of land, and the even larger aspirations he had for it. He received a 27-year lease from Columbia University and began construction in 1930, paying for additions with Standard Oil stocks and working out a line of credit with the Metropolitan Life Insurance Company. The center’s construction took three years and Rockefeller financed the $100 million project himself.

Upon its completion in 1933, it was–and still is–the world’s largest privately owned complex. But were it not for one fateful transaction, Rockefeller Center might have lost that title to a “Dream City” by developer William Zeckendorf, Sr. just a few avenues away.

9. The Number of Visitors to the Center Throughout the Years Rivals Whole Cities

On any given day, Rockefeller Center attracts a crowd of about 350,000 people. If Rockefeller Center were its own city today, it would be the 54th largest city in the country, right after Honolulu, the capital of Hawaii.

8. The Center Has a Series of Secret Rooftop Gardens

Don’t forget to look up! 620 Loft and Gallery, part of 620 5th Avenue, is part of an indoor/outdoor space with views of St. Patrick’s Cathedral that can be rented for weddings and events. It was also a film location for the original Spiderman movie. On the symmetrical rooftop across the way is a perfectly manicured rooftop that’s connected to the Tishman Speyer office. So basically, take any meetings you can at Tishman Speyer.

7. The Most Famous American Vintage Skyscraper Photo in History was Taken Atop 30 Rock

You know this photograph. It has been copied and parodied hundreds of times throughout history, so often that it stands among the ranks of Salvadore Dali’s ‘Persistence of Memory’ and and the stern-faced, pitchfork-wielding couple of ‘American Gothic.’ This photograph, ‘Lunch Atop a Skyscraper, was taken in 1932 on the 69th floor of the RCA building, now the GE Building, otherwise known as 30 Rock. On another note, it is believed, through archival records, that though the men pictured were real construction works, the photo was in fact staged by Rockefeller Center and published in The New York Herald Tribune to promote the brand new skyscraper.

6. Tours Have Been Held In at Rockefeller Center Since its Founding

‘Saturday Night Live’ head-writer Tina Fey left the show in 2006, but we forgive her, because she gave us ’30 Rock,’ and most importantly, she gave us Kenneth the Page. Pages have been guiding tourists through NBC studios in the GE Building for almost 80 years, and they still wear that outfit. Television host Regis Philbin, who now holds the world record for the most time spent in front of a camera, began his career at 30 Rock as a page. Additionally, at the height of World War II in 1943, Rockefeller Center’s pages were all female. What’s not on the tours anymore: visits to the rooftop garden where there was once (and perhaps still are) koi fish swimming in the ponds.

5. Two Holdout Buildings Almost Stopped the Building of Rockefeller Center

A Magnolia Bakery currently occupies the former Hurley’s, a bar and saloon that opened in the 1890s and later became a famed watering hole for the media industry, ironically based largely in Rockefeller Center. The saloon had also operated successfully through Prohibition where the ground level flower shop led to the more popular speakeasy below. The three Hurley brothers were hardly fazed by Rockefeller, asking for an absurdly high sum to underscore their refusal to leave. As one Hurley said “I’ve seen sonofabitchin’ Rockefellers come and sonofabitchin’ Rockefellers go and no sonofabitchin’ Rockefeller’s gonna tear down my bar.” Less theatrical but equally firm in his refusal to leave, John Maxwell simply refused to negotiate at all, whether in seriousness or not. Forced to build above and around the two townhouses, the 70-story 30 Rockefeller Plaza remains sandwiched between two three-and-four story structures.

4. Radio City Music Hall Has a Hidden Apartment

Rockefeller Center’s iconic Radio City Music Hall should probably have its own 10 secrets. Aside from hosting the Christmas Spectacular, featuring the Rockefeller Center Rockettes, since 1933, the venue was originally a high-class entertainment venue, conceived to put Rockefeller Center on the map.

The architect of  Radio City Music Hall, Edward Durrell Stone, and its interior designer Donald Deskey, built an apartment inside Radio City for famous entertainer Samuel “Roxy” Rothafel. With the same Art Deco design, the apartment was the perfect place to entertain the greats of Hollywood’s golden era like Alfred Hitchcok, Samuel Goldwyn, Olivia de Havilland. As reported by Atlas Obscura, the “20 foot high ceilings covered in gold leaf, and walls decorated floor to ceiling with plush drapes, Roxy’s apartment was as mesmerizing as his opulent stages shows below.” It is reportedly still in pristine condition.

3. It Was the Seat of British Intelligence’s American Operations During World War II

International Building North, a structure in the original complex, was where British Intelligence set up their base of operations throughought World War II, beginning with Hitler’s occupation of Poland. The building’s room 3603 was additionally used as the headquarters of Allied Intelligence, and functioned as the office of Allen Welsh Dulles, who would become the civilian director of the yet-to-be-formed Central Intelligence Agency.

2. The Lights on the Rockefeller Center Tree Stretch 5 Miles

The iconic Rockefeller Center Christmas Tree is as much a staple of a new York Christmas as the Rockettes or the Christmas Spectacular. While the first tree in 1933 was only about 20 ft tall, put up by works on Christmas Eve. Today, the tree can be anywhere from 60 to 100 ft and is put up almost a month in advance. While previous trees were gifted to the Rockefeller family by wealthy donors, growing popularity has warranted Rockefeller Center to be just a bit pickier.

Today, officials embark on a helicopter tour of upstate New York, New Jersey, Vermont, Ohio, and Pennsylvania. The Tree is delivered to Rockefeller in the middle of the night (some have caught it on a large flatbed truck en route) , and decorated with thousands of LED lights before being hoisted to the center of 30 Rockefeller Plaza. Plugged in end to end, the lights on the Rockefeller Center tree would stretch 5 miles, about the distance from 110th Street to 14th Street along Broadway. (For reference, the perimeter of Central Park is 6 miles). To add to the feat, the Swarovski star at the top weighs 550 pounds. The tree does not require water for the entire month because its enormous size can retain enough water to keep it alive.

1. The GE Building’s Original, Scrapped Lobby Mural Contained a Portrait of Vladimir Lenin

Detail of recreation of ‘Man at the Crossroads’ with Vladmir Lenin

Rockefeller Center contains a great many pieces of art, from the iconic Prometheus and Atlas statues to the murals all around 30 Rock, for the most part dealing with the progression of man, philosophical and technological, through the ages. However, one such commission by the socialist artist Diego Rivera, then financed by Rockefeller’s wife, was taken down shortly after being installed in the lobby of the GE Building due to accusations of it containing Communist imagery.

Diego’s color fresco, dubbed ‘Man at the Crossroads,’ was said to contain an image of Vladimir Lenin and a Soviet Russian May Day Parade. Nelson Rockefeller, John Jr.’s son, having wanted either Henri Matisse or Pablo Picasso to design the lobby of the GE Building, lobbied to have the mural destroyed before it was finished, despite protests from artists trying to get it moved to the nearby Museum of Modern Art. The mural was ultimately destroyed.

Next, read about the proposed UN headquarters that might have rivaled Rockefeller Center in size and grandeur and discover the Top 10 Tallest Buildings in NYC today. Get in touch with the author @jinwoochong.