Flight Vienna - Funchal, view in NW direction over the Montes Vascos (Basque Mountains) with the town of Irurtzun in the right centre. The Sierra de Andía (Beriain, 1493 m) in the upper left centre clearly represents a tectonic fold. It is separated from the Sierra de Aralar (Irumugarrieta, 1431 m) in the upper centre by the Araquil Valley.