More than just the public library, this stately Greek Revival edifice is a sight in itself. The 2nd-floor Great Hall has hosted such notables as Ralph Waldo Emerson and abolitionist Frederick Douglass. Nationally known opinion makers still speak here today; ask about the summer lecture series, and look out for classes and concerts (there's a useful calendar online).
Nantucket Atheneum
Top choice in Nantucket