The eighteenth stage runs along the crest of the boundary between Gipuzkoa and Navarre, among magnificent beech tree and oak forests, bordering the Natural Park of Aralar. After crossing the pass of Etxegarate, you enter the Aizkorri-Aratz Natural Park and the “Parzonería” of Gipuzkoa and Araba/Álava. The stage ends at Mikelete’s house, at the entrance to the tunnel of San Adrián, a natural pass through the mountains of the peaks of Aizkorri and Aratz, where the Roman trade route connecting the squares of Astorga and Bordeaux used to cross; the remains of the Roman road and the settlements are still preserved.
The stage begins at the Park house. From there, you should walk some one hundred metres along the NA-120 highway eastwards and take a turn-off that is the entrance to a house. At this point, a path leaves that begins climbing through a beech grove. For 1.5 km, you climb an incline of 300 m along a very steep forest path —up to 30%— which zigzags across the hillside of Mount Askoa until it reaches the top in the vicinity of the peak of Txaradigorri.
From the top of the mountains, the trail continues for over ten kilometres along tracks and old forest paths, which follow the mountain range summit, passing by peaks such as Zelatamuño, Hirumugarrieta, Beitzeta and finally the Sierra of Albania. Via the latter, you descend some two kilometres as far as the pass of Etxegárate, entering the Gipuzkoa region of Goierri, specifically through the municipalities of Zegama and Idiazábal and the “Parzonería” of Gipuzkoa and Araba/Álava. This part covers the southern boundary of the Natural Park of Aralar.
Along this route —as far as Etxegárate— you cover extensive Atlantic forest areas, mainly beech groves that dominate the vegetation on the top parts of the mountains. Beech groves constitute one of the Atlantic formations par excellence; they are proper to humid environments with no summer drought. These forests offer trekkers extremely attractive scenes in the different seasons of the year, with significant colour contrasts. Visiting them in the autumn is highly recommended, especially in the months of October and November, the season when the cover of beech trees (Fagus sylvatica) turns a very bright shade of yellow and red. Although the beech grove undergrowth is rather poor, given that no light can get in, you can see other species —holly trees (Ilex aquifolium), hazelnut trees (Corylus avellana), elm trees (Ulmus sp.), maples (Acer sp.), and linden trees (Tilia sp.)— in some of the cleared areas the Trail passes through.
On this route, you can also see remains of megalithic constructions, such as the dolmens of Zelatamuño, Argonitz and Bernoa, which can be found in the area surrounding the path, on its way through the mountain watershed. These constructions reveal the existence of ancient settlers on these lands.
The pass of Etxegárate is the crossing point by road between Gipuzkoa and the River Arakil corridor, in Navarre, connected via the A-I highway. In order to following the route, you have to cross this road, taking a forest track in a westerly direction next to a service station. The track runs across uneven land for some four kilometres. It then crosses a mosaic of forest plantations and mixed beech grove and oak patches, until it ends in Otzaurte. This small village in Zegama is the main gateway to the Aizkorri-Aratz Natural Park, where you can visit its Wood Interpretation Centre.
From Otzaurte, you should cross the GI-2637 highway and follow a gravel track that heads in a south-westerly direction, climbing through the beech grove of Arkalin as far as the recreational area of Beunda, a point that is frequented by trekkers, from where you get your first view of the peak of Aratz. From this point, you should continue along the gravel track for some 250 m and then take a turn-off on the right along a path that follows the ridge of a small hill —crowned by the peak of Añabaso—. After beginning the descent, passing next to the small peak of Aldaola, you link up with a track that you soon leave once again. You should take a path that crosses a stream via some wooden walkways and gently climb until you intersect a track that leads, after a few hundred metres, to the section’s final destination, Mikelete’s shelter. It is located at the foot of the tunnel of San Adrián and from there you will have magnificent views of the Ubiergo stream valley and the Aratz peak.
Barely 250 m up the slope, you can visit the chapel of the Santo Espíritu, an old hospital for pilgrims on St. James’s Way, which passes under the tunnel of San Adrián.
This stage is hard to cycle. To begin with, the first part that climbs through the beech grove — from Lizarrusti to Txaradigorri— because of its steep slope, which does not allow you to cycle up, not even if you carry your bike on your shoulder. If you should reach the top, the next kilometres along the summit of the mountains, as far as Etxegárate, are tough as they cover old dirt paths and forest tracks. From Etxegárate as far as Otzaurte, there are also some time-worn forest tracks that make cycling very difficult. Finally, some sections of the part from Otzaurte as far as Mikelete’s house are extremely difficult to cycle along although, in this case, there are viable alternatives along accessible tracks.
The Aizkorri-Aratz area separates the provinces of Araba/Álava and Gipuzkoa, constituting one of the Basque Country’s main mountainous areas. The Natural Park covers 15.919 ha while the Site of Community Importance embraces 6.778,84 ha, with their territorial area partially overlapping. In addition to recreational uses — mountaineering and trekking—, the land is mainly used for forestry and livestock breeding. It is one of the most important grazing areas for “latxa” sheep; in fact, you will come across countless shacks or "saroiak" where shepherds used to live to take care of their flocks during their stay in the mountains.
The landscape is abrupt, with significant, complex limestone reliefs and generalised karstic phenomena, which give rise to highly diverse formations, shaping a landscape of great aesthetic and ecological value. Its essential nature is formed of geological structures: the limestone faces of Aizkorri-Aratz and the Crags of Eguino, the slopes of Kurutzeberri, Orkatzategi and Aloña, the depressions of Urbia, Degurixa and Alabita and the canyons of Arantzazu and Jaturabe.
This extensive mountainous area has considerable and varied forest masses, with noteworthy stretches of autochthonous forests formed of calcicolous and acidophilous beech groves, Pyrenean oaks, gall-oaks and Holm oaks. It also features mountain pastures, heathers and humid enclaves of great botanical interest, such as the incipient fens of Arbarrain (Altzaina).
The Aizkorri-Aratz area is an important biogeographical corridor between the large Pyrenean and Cantabrian mountain ranges housing habitats and shelters for diverse species of fauna. Its eastern end is one of the main passing points for migrating birds—doves, geese and cranes— which fly across the Valley of the River Oria. In addition, in the man-made reservoir of Urkullu, water birds and amphibians settle due to its physiogeographical features, making it the main interior wetland in Gipuzkoa.
The General “Parzonería” of Gipuzkoa and Araba/Álava is one of the three “parzonerías” existing in the province of Gipuzkoa, next to that of Enirio Aralar and the “Parzonería” of Gipuzkoa.
In administration terms, it is a territory formed of mountains which is jointly owned by four town councils of Gipuzkoa: Idiazábal, Segura, Zerain and Zegama (belonging to the region of Goyerri); two from Álava: San Millán and Asparrena (belonging to the Cuadrilla de Salvatierra); in addition to another municipality in Álava, Zalduendo, which participates in the uses in conjunction with Asparrena.
The “Parzonería” occupies the mountains of Altzania, San Adrián and Urbía, covering over 2.400 ha. It was created in the 15th century after the town hall of Segura bought the mountains forming it from Fernán Pérez de Ayala. The town hall was the visible title in the deeds of sale and Idiazábal, Legazpia, Zerain and Zegama took part in the transaction. At a later date, Legazpia marked out the boundary of its part and ceased to participate in the “Parzonería”.
It is not known exactly when agreements were reached with the Álava municipalities of San Millán, Asparrena, Zalduondo and Salvatierra for the joint use of the mountains, but it is thought to have been in the 15th century. In the early 20th century, in 1916, Salvatierra decided to leave the community. Also, on an unknown date, the “Parzonería” segregated a space in its most eastern area for the sole use of the four town councils of Gipuzkoa, giving rise to the “Parzonería” of Gipuzkoa.
The “Parzonería” is managed sustainably, setting limits for the use of the mountains and furnishing care and afforestation. The costs and profits of the “Parzonería” are allocated among the villages on the basis of regarding the assets as being divided into 220 portions of which Segura holds 52.75, Idiazábal 49.25, Zegama 47, Zerain 16 and the rest is distributed equally between San Millán and Aspárrena with Zalduondo.