The Mercado San Pedro (Túpac Amaru, 6 a.m.–7 p.m.), near the San Pedro train station, has amazing fruit and vegetables. Come here to try the unique and delicious granadilla and chirimoya and cheap juices, but keep your eyes out for pickpockets and those who silently slice backpacks with razors to steal the goodies within.
Several blocks past Mercado San Pedro toward Avenida Ejercito is El Baratillo, which on Saturday morning is full of the most fascinating secondhand wares. If you have time to browse properly you can find some real treasures, but be careful with your valuables.
El Molino, just behind the central bus station, is Cusco ’s largest black market and has everything. It is a little out of the center of town, so it’s best to catch a cab. Not many tourists come here, but as long as you hang onto your wallet you will be fine.
The largest supermarket is Mega (Plaza Túpac Amaru and Matara). Gato’s Market (Portal Belen 115) and Market (Portal Mantas 120) are both on the Plaza de Armas; they’re small and pricey but do stock hard-to-find imported products.