The Midtown branch underwent a $200 million renovation.
NYPL's largest and busiest branch has more than 1.7 million visits a year and an annual circulation of 2 million items.
The building's modern interior and inspiring design is by Dutch architect Francine Houben of Mecanoo architects with New York City-based firm Beyer Blinder Belle.
Tuesday at 1 p.m., the lower level through the fifth floor will open for the first time for limited browsing and by-appointment computer use.
The new library has the capacity for 400,000 books, five levels of open, browse-able book stacks, and two floors of classrooms and meeting spaces.
The 20,000-square-foot Pasculano Learning Center-the Library's largest adult learning center-will provide a seamless continuum of educational opportunities to support lifelong learning (including technology training, ESOL and citizenship classes, and so on).
There's also a new 26,000-square-foot floor of separate spaces entirely for kids and for teens; there were no dedicated spaces for children or young adults in the former Mid-Manhattan Library.
It also has the only free and public rooftop terrace in Manhattan.
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