La Merced is the biggest of Mexico City's covered markets, occupying several blocks just east of the Zócalo. It is the principal wholesale point for fresh produce in the city, with hundreds of stalls selling everything from dried chillies, moles, and herbs to whole pigs' heads, mountains of nopal cactus paddles, and twenty varieties of mango.
The sweets section in the northern hall is the surprise — sugar-coated camotes (sweet potato candies), tamarind candies dusted with chilli, marzipan figures, a Willy-Wonka maximum-sugar overload. Eat at the food stalls along the central aisle: pozole, tacos de canasta, blue-corn quesadillas. Visit in the morning; afternoons are crowded; the area immediately outside the market is a bit rough.