This is "is a series of walking tours through areas of New York ... [that] seeks out still-visible traces of the city's layers of history." Topics include Manhattan's photo booths, Weegee's naked city, Brooklyn's freedom trail, immigrant communities in Flushing (Queens), gangsters and ghosts in Hell's Kitchen, P.T. Barnum's New York, and more. Interactive maps feature audio and video segments. From The New York Times.