The Mercado Pino Suárez is the public market of the old town and the place to eat cheaply. The building dates from 1899, an iron-framed hall in the French style that was common in Mexican market construction at the time. Downstairs is produce, butchers, fish, and dried-chile stalls. Upstairs is a ring of fondas — tiny family-run kitchens, six or eight stools each, serving the same handful of dishes for the last fifty years.
The marlin tacos at the front-right corner, the menudo on weekends, and the breakfast chilaquiles are the things to know about. None of it costs more than a couple of dollars, and the upstairs gallery is one of the better people-watching perches in the Centro.