Gorge of the Ayuda river Nature · Condado de Treviño, Ebro, Burgos Image of Condado de Treviño, not of the place itself. The Ayuda river, called Ihuda in Basque, rises in the Montes de Vitoria, near Oquina, and is a tributary of the Zadorra, which in turn flows into the Ebro. Its greatest beauty lies hidden in the gorge it carves from south to north between the villages of Oquina and Sáseta, with the typical appearance of a Cantabrian mountain river amid beech forests and varied woodland; the Rodavieja waterfall stands out within it. The canyon crosses the Condado de Treviño, enclosed within the province of Burgos and bordering Álava, before the river reaches a flatter area at Urarte, a Basque place name meaning 'between waters'. Rock-cut hermitages open into its walls, and birds of prey that hunt over the county's grain fields nest above them. Photo: Basotxerri (CC BY-SA 4.0) What to see and do in Condado de Treviño