The Casa de la Cultura is Ecuador's national cultural institution, and the Manabí chapter in Portoviejo runs a programme of rotating exhibitions, live music, theatre and craft workshops. The building has gallery space showing work by local and national artists, and a small permanent collection covering Manabí folk traditions including coastal weaving, ceramics and the crafts associated with Panama hat production.
Check what is on when you arrive — the programme is uneven but good things happen here regularly, and entry is usually free or very cheap.