This geological structure is an excellent excuse for a walk along the amazing cliffs between Getxo and Sopelana. It offers some of the greatest views of the Bay of Biscay. Along the way we will find interesting spots such as Aixerrota Mill, built in 1727, the Lighthouse, or La Galea Fort, standing on top of the cliff. The latter was built in the 18th century to protect the commercial ships heading towards Bilbao. The visitor should not miss the dunes of Aizkorri and Barinatxe, whose native vegetation is being restored. This kind of habitats has disappeared almost completely from the Bay of Biscay.