The Mercado Central is the city's main fish market and one of the great Victorian market buildings in the Americas. The enormous iron-framed hall, dating from 1872, is filled with fish stalls piled high with the extraordinary variety of Chile's Pacific coast: congrio (conger eel), reineta, lenguado, locos (abalone), erizos (sea urchins), centolla (king crab), and everything else pulled from some of the most productive cold waters in the world.
The best way to use it is to have lunch. Sit at one of the seafood restaurants in the central hall (not the tourist-priced ones around the outer edge) and order a plate of ceviche, paila marina (mixed seafood broth), or congrio frito. The market restaurateurs are skilled at what they do, and the quality-to-price ratio at lunchtime is excellent. Come before 1 p.m. on weekdays to avoid the worst of the lunchtime rush. The market is in the northern part of the centre, a short walk from the Plaza de Armas.