See the main page to approach to Urkiola and col of Asuntze.
The trailhead and the first part of the route are the same of a lot of people (this mountain is very popular), you must to follow the normal route to the summit of Anboto.
Another option is trail head in Atxarte but I think is a little bit complex for the foreigners. (note: it's the track of GPX)
Note about track GPX: it was taken with my old GPS Magellan and it's not very accurate because when I was climbing the GPS was behind my body in some places and it lost a few of satellites. It's curious that this track signalled the highest point in Elgoin and not in Anboto but it was a mistake.
Route description-The ridge
Beginning in the summit of Anboto (1h 45 min).
The long ridge SE-NW has 2 sections divided for a wide col (col of Larrano)
. You must to know that you can leave the ridge only in the col (or returning for the ridge).
The first section
it's a little bit exposed with grade I and I+ in some places but it's easy. The rock is very good (dangerous when it's wet) and the landscape is spectacullar descending and ascending across the other 2 summits: Elgoin
. Finally we reach a green hillside to descent to the col of Larrano
(3h) with the little hermit of Sta Barbara.
The second section
: after the little peak of Punta Larrano
we reach a complicated labyrinth of ridges of grade I or I+. The start is over the ridge and for the west side but the continuation it's across the less exposed East side with repises of rock and grass to reach some little peaks less important (Larrano Zorrotza and Larrano Urkulu Puntea). After this little peak you go to the right (east) descending. You can reach a small terrace in the bottom of the wall of the Paso del Diablo
. This is a wall of 4 meters of grade II+ very exposed to the right side. Generally for the mountaineers it's not very complicated. After the wall we climb immediately across a chimney of 20 meters of grade I+ (easy) to the upper ridge (total 24 meters, be carefull!). The last summit is visible and the ridge is very confortable from here to the vertex of the summit of Alluitz (1040m)
(4h). It's a good moment for the rest enjoying of the panorama.
across the north side of Alluitz for a long hillside without complications to reach the col of Artola
. In this point under the peak Astxiki we turn in SW direction to reach the plains of Guenzelai and finally the col of Astuntze of Urkiola.
Note: it's possible to climb the ridge in direction NW to SE, Alluitz to Anboto, but in this case you must to descent the Paso del Diablo. I think this step-crossing is less impressive in the ascent (the descent it's more dangerous and even it's advisable the use of a rope).
Good boots, water, cap,...
Not rope necessary, only a little experience.