The Mercado Central runs in a block of low concrete halls a few streets east of the Plaza de Armas, busiest from dawn until about ten in the morning. The food side is where the visit happens: stalls heaped with aguaje (a scaly orange palm fruit eaten in pulp form), camu camu (a tiny red berry with extraordinary vitamin C content), cocona, carambola, macambo, and the soft white chonta palm hearts used in regional salads.
Walk through and you also see river-fish stalls — paiche, doncella, gamitana — laid out on ice or fresh from the morning peque-peque boats. The juice stands at the entrance will mix any combination you point at. It is a working market, not a tourist one; cameras are tolerated but a brief conversation goes further.