Keep an eye out at Antigua Lonja de Pescado — you're sure to discover some treasure or trinket among the stalls here. After you've had a good look at the wares, grab something to eat from one of the nearby food vendors.
This community marketplace is located in El Puerto de Santa Maria. Once you've seen everything you want to at Antigua Lonja de Pescado, pay a visit to nearby Cadiz Cathedral, Plaza de Espana, and Torre Tavira.