On this route, which circles Oiz mountain, we will encounter some very impressive sights: the coast of Urdaibai, some Guipuzcoan mountains, Gorbea mountain and the imposing mountains that surround Durango.
We set out from the Plaza Madalena in Durango, through Francisco Ibarra street and we cross the N-634 towards Iurreta.
Once we have crossed the main road, we turn right at the first junction towards the chapel of San Mamés. We cross the bridge over the motorway and we go for 2 km up a road which is fairly steep until we arrive at the chapel of San Juan. Then, after another 300m, we turn left in the direction of Goiuria (BI-3341). A further 900m on, we take the road towards Oiz mountain. We pass La Forestal and continue along the wider track until we get to the chapel of San Cristóbal of Oiz (km 12.8), the highest point of this excursion.
We continue on, and on our left we follow a narrower cement road that descends rather steeply (about 2km). Below at the junction (km 15) we turn right towards the village of Kortaun. Take care at km 18, because here we leave the wider track and turn right, entering the woods.
Soon after, we cross a fence, and then another.
For the next 3.5 km we find ourselves on a mountain track. On arriving at the Colegiata of Zenarruza (km 21.5) we take the main road BI-4401. After 800m we leave the main road (km 22.3) we go up a rather steep track on the right, and this will take us to Muñozguren. This stretch of 2.3km has some very steep hills.
Arriving at the top, we take a left towards Muñozguren (km 24.6). Then we head down towards Trabakua on the main road BI-4403. In Trabakua we take the BI-633 that leads us down to Berriz, but shortly before we get there (km 34.7) we go up to the village of Besoita, situated on the right, and then on to Andikoa.
Finally, we descend to Ereña, by way of farm roads, and from there we return to Durango.