The Museo de Arte de Mazatlán gives the old centre a cultural stop beyond the theatre, plazas, and restored facades. It hosts exhibitions of regional and Mexican art, with a scale that suits a casual visit rather than a long museum day.
Use it as part of a Centro Histórico walk, especially if you are already around Plazuela Machado. Mazatlán is often sold through beaches and seafood, but the museum is a reminder that the historic core has a quieter arts scene worth leaving the resort strip for.