The Stephen A. Schwarzman Building, commonly known as the Main Branch or the 42nd Street Library, is the flagship of the New York Public Library system. Located at Fifth Avenue and 42nd Street, it is a Beaux-Arts masterpiece and a National Historic Landmark, easily recognized by its iconic lion statues, ‘Patience’ and ‘Fortitude.’ 
Interesting facts…
The original design competition was won by Carrère and Hastings, then relatively unknown architects, who beat out more established firms for the commission.
The building is a Beaux-Arts masterpiece, designed by Carrère and Hastings, and was the largest marble building ever constructed in the U.S. when it opened in 1911
The library actually sits atop the former Croton Reservoir, a 19th-century water supply for New York City. Traces of the reservoir remain visible in the library’s floor