Castelo de San Antón guards A Coruña's harbour from a rocky islet that is now tied to the city by land. The old fortress setting is half the reason to come: stone walls, sea air, and views back toward the waterfront give the museum a strong sense of place.
Inside, the archaeological collection covers Galicia from prehistory through Roman and medieval finds. It is a good follow-up to the Tower of Hercules because it keeps you thinking about the city's long relationship with the Atlantic.