A small but worthwhile cultural centre half a block off Plaza Colón, housed in a restored early-twentieth-century townhouse. The collection rotates — historical photographs of Mayagüez, work by local painters, exhibitions tied to the city's literary figures — and the staff are knowledgeable and happy to talk.
Worth a stop especially if the Teatro Yagüez is closed and you want a sense of the city's cultural life beyond its architecture. Admission is free or a small donation.