Western Mountains. This range of mountains generally follows the Gipuzkoa-Biscay watershed. With the exception of the part of Aramayona which, being on the Cantabrian slope, is in Alava. Its main peaks are: Murugain (775 m.), Udalaitz (Udala, 1,092 m.), Intxorta (737 m.), Urko (791 m.); Max (767 m.) and Arno with two summits (612 m.). The foothills that start at the headwaters of the Urumea, Leizarán, Araxes, Oria, Urola, Deva and tributaries form boxed-in valleys. The mountains are gradually losing height, but even on the coast itself there are heights of 500 and 400 m., such as Jaizkíbel (549 m.) and Mendizorrotz (411 m.). From the latter to the west, the heights drop notably, remaining 250 and 150 m.