The Mercado de Coyoacán is the traditional covered market a few blocks north of the main plazas, a maze of stalls selling flowers, produce, piñatas, spices and household goods. For most visitors, though, the draw is the food: the market is famous citywide for its tostadas, piled high with ceviche, tinga, crab or octopus at a row of busy counters where you queue, point and eat standing up.
It is cheaper, more local and less polished than the souvenir stalls around the square, and a good place to eat your way through a Coyoacán afternoon. Busiest and best at weekend lunchtime.