As the French Basque Country is only 30 minutes away from San Sebastian, we recommend that you spend a day visiting the beautiful villages of St. Jean de Luz, Biarritz or Bayonne.
You could also stop in the last town before crossing to France, Hondarribia, a beautiful town and the best-preserved walled town in Gipuzkoa. Its wide walls enclose a medieval layout, with ancestral buildings, narrow streets, cobblestones... and heritage and history.
Hondarribia
With a small boat you can cross to Hendaye, first town in France, so nice!
Hendaye