Bayonne's natural-history museum is a small, focused stop rather than a blockbuster attraction. Its strength is local context: birds, mammals, geology, and river environments from the Adour basin, the Basque coast, and the nearby Pyrenees, all of which help explain the landscape beyond the old town streets.
It works best as a quiet add-on to a walk through the ramparts and green spaces north of the centre. Travellers with children, birders, or anyone heading onward into the Basque countryside will get more from it than visitors trying to tick off Bayonne's main monuments in a short visit.