The estuary of river Urdaibai has many attractions that can be enjoyed in a short trip from San Sebastián. The hermitage of Gaztelugatxe (set as Dragonstone in the Game of Thrones series) is a good start to enjoy the sea views in contrast to the mountain. Then, the coastal town of Bermeo allows you to see firsthand how the old fishing traditions are maintained in the present.
Finally, from Bermeo, you reach Gernika, where rural and agricultural traditions are mixed with their varied history. Gernika is the reference town in Basque history, since here is the ancient tree where the medieval kings of Spain swore to respect local laws. It is also where the German bombing took place during the Spanish Civil War that destroyed much of it.