Deep in the subway system below Times Square, and passed by thousands of commuters and tourists every day, there’s a white door that goes largely unnoticed.

It’s tucked away on the end of the platform of Track 1 on the S shuttle between Grand Central and Times Square-42nd Street, closest to the 42nd Street exit. At first glance, it’s similar to the many doors that can be found in many MTA stations, storing supplies or equipment. But where those lead into utility rooms, offices, and generators, this white door was once a portal into a glamorous world. 

Atop the door is a faded metal sign which simply says “KNICKERBOCKER,” and behind it lay a secret entrance to the bar of what was once one of New York’s most splendid accommodations: John Jacob Astor’s Knickerbocker hotel.

Above ground, on the corner of Broadway and 42nd Street, the Knickerbocker was a Beaux-Arts masterpiece. Built with Astor’s millions in 1906, it had over 500 rooms, with space in the restaurants and bars for 2,000 revelers.

Throughout the Gilded Age, the hotel was a centerpiece of Times Square. It was an epicenter of refined elegance, and commonly known as the “42nd Street Country Club.” A 30-foot mural of Old King Cole and his Fiddler’s Three, painted by Maxfield Parish, hung over the bar, where the bartender Martini di Arma di Taggia is rumored to have invented his famous namesake cocktail in 1912, and served it to John D. Rockefeller. 

When Astor died on the Titanic, his son took over. The hotel soon fell out of favor in the Prohibition era. Parish’s mural was moved to the St. Regis Hotel, and the old building was converted into offices for Newsweek magazine. 

The hotel reopened in 2015—but so far, there aren’t any plans to bust open the secret back door to what was once one of the city’s finest jewels.

Update as of January 2020: Renovations to the tracks currently obscures the view of the secret door.