River Deba. It rises in the Elgea mountain range at an altitude of 825 metres. The two main streams from which it originates join near Andra Mari Dorletakoa. In its 58-kilometre course, it crosses the Leniz valley, the villages of Gatzaga (Salinas), Escoriatza and Aretxabaleta. On its course towards the north, it receives numerous streams that increase its flow. When it reaches Arrasate (Mondragón), it receives the River Aramaiona on the left, which comes from this valley in Alava on the Gipuzkoa side of the river. Mondragón and Bergara, in San Prudencio, it receives the River Aránzazu from Oñati. In Bergara it is joined by the Antzuola from the port of Deskarga. Further downstream from Vergara, it receives the streams coming down from Elgueta on the left and from Mount Elosua on the right. From Mártires to Soraluze, the River Deba flows through a narrow gorge. At Maltzaga, on its left bank, it is joined by the river Ego from Eibar. From Soraluze to Elgoibar it makes a big bend to cross Mount Muneta. On its way from Elgoibar to Deba it passes through Alzola where it receives, on its right, the Kilimón. It continues through Mendaro and flows into the sea at Deba beach.