New York Public Library, Jefferson Market Branch

Ensconced inside a Victorian Gothic city landmark (a former courthouse), the children’s library exudes a Harry Potter–esque feel, thanks to arched stained-glass windows, ornate carved-wood doorways and several original, mural-size artworks—most done by former librarians. Mini goths can even climb the old-school, spiral staircase, inside the tower, to the adult library on the second floor. Kids also flock to the branch’s storytimes and craft sessions, plus a slew of festivals, such as October’s pumpkin-painting extravaganza, held in the library’s public garden.