Answer

NYC: The NYU Libraries flagship, Elmer Holmes Bobst Library, can be found on Washington Square. Addresses for all affiliated facilities can be found in the NYU Libraries Locations page. 

NYU Shanghai: The only entrance to the NYU Shanghai Library is on the 5th floor of the HiTime Building (North Building). The library space includes the north side of the 5th floor, the west side of the 5th floor, and the north side of the 6th floor. For more information, please refer to the library floor map.