Great travel writing consists of equal parts curiosity, vulnerability and vocabulary. It is not a terrain for know-it-alls or the indecisive. The best of the genre can simply be an elegant natural history essay, a nicely writ sports piece, or a well-turned profile of a bar band and its music. A well-grounded sense of place is the challenge for the writer. We observe, we calculate, we inquire, we look for a link between what we already know and what we're about to learn. The finest travel writing describes what's going on when nobody's looking.