The coastline near Bermeo, between Cape Matxitxako and Bakio, is well-known for its spectacular eroded landscape full of caves and natural rock arches and is classified as a Protected Biotype, both for the quality of the water and the historical interest of the area, which was first documented in the 11th century.
At the heart of this coastline stands the magical promontory of San Juan de Gaztelugatxe, which forms a peninsula out into the Bay of Biscay and is joined to the mainland by a bridge built on the rocks. Crowned by a small chapel eighty metres above sea level dedicated to St John, you can reach it by climbing 231 steps up a rocky slope. The rock simulates a castle in the sea, called Gaztelu-aitz (castle rock) or Gaztelu-gache (harsh or difficult castle) in ancient times. The small island of Akatx can be seen out to sea.