Dreamed up by a pair of American philosophy majors, this atmospheric bookshop a few steps down from Oia’s pedestrian "main street" is packed to the rafters with novels, travel books, rare first editions, and, of course, Greek mythology and philosophy. (Look up, and squeezed between the rafters and bookshelves, you’ll see bunks where employees bed down after closing time.) The easygoing, erudite staff and the soundtrack of Nina Simone and Ella Fitzgerald make it hard to leave in a hurry (or empty-handed). Journals and totes imprinted with Greek quotes make great souvenirs. The foldout map of Santorini, highlighting the owners’ secret swimming spots and watering holes, is all you need for an authentic experience of this most touristy of Greek islands.