Wales's oldest independent museum, founded in 1878 and tucked into the old castle ruins on Castle Hill. The collections cover Tenby's maritime, geological, and social history, with a strong art gallery showing works by the local-born siblings Augustus and Gwen John, as well as Nina Hamnett and others associated with the town.
It is small enough to see in an hour but well done — an unhurried overview of how Tenby grew from a Norman garrison to a Victorian resort, and a good shelter when the weather turns.