The starting point for this walk is the car park in front of the Ola cider factory in Irun. To get there by car, see the "practical information" section below.
You will need a headlamp or torch to visit the bunkers.
(S/E) From the car park, head back towards the car park entrance and cross the bridge on the right. Turn right and continue along the road, preferably on the left-hand side of the carriageway, taking care to keep to the left, until you find the first path (cement track) on the left, which you should take. You will come to a fork in the road.
(1) Take the path in the middle. Walk along a stream, then come to a larger path.
(2) Leave the previous path and take the path on the right. This is a pretty path through the woods that runs alongside the river. Pass the ruins and join a wide path. Turn right onto this until you reach the cement road. Follow this road to the right. Pass a fountain (non-drinking water) and continue until you reach a fork in the road.
(3) Start by heading towards the garden on the left, where there are two very large trees, to contemplate the large statue of a seated man wearing a Basque beret and smoking his pipe. Continue along this path and, at the first junction, turn left. You will come across a large number of pidgeon hunting huts.
(4) Come to a road and turn left. Head towards the large antenna and take the grassy path that runs past it on the right. You will reach the San Martial summit at an altitude of 249 m (which is indistinguishable from the rest of the route, except for the fact that you come back down) and follow this little path. Pass through an old area surrounded by small stone walls and continue until you reach the wide track.
(5) Turn left and pass the first children's play area with a picnic table and bench. Continue straight ahead (at the one-way sign) and you will come to a second children's play area (also with a table and bench). Walk the last few metres uphill.
(6) This will take you to the Ermita de San Martial (worth a visit), where you can enjoy a splendid view over the Bay of Hendaye, the village of Hondarribia opposite and the Jaizkibel massif. There is also a cantina here where you can quench your thirst.
(7) Go to the other side of the hermitage and climb down the steps to follow a small path. This is the part of the hike that needs to be approached with care, as the descent is steep at times.
(8) Reach the first bunker and visit it (torch required). Continue downhill to the second bunker to visit. Continue downhill(carefully, as this is the most complicated part) for around ten metres until you reach a well-marked path that you should take to the right. From this point on, there are no further difficulties. Continue downhill along this path through the forest. When you reach a tarmac road (GI-3453), cross it carefully as there is a little traffic and take the small path exactly opposite.
(9) Join the GR®-11, follow it to the left, cross the tarmac road (GI-3453) again and continue along the path. Reach the road leading to the car park at the level of a motorway bridge.
(10) Cross the bridge and continue along the pavement to the left, then cross to the other side of the river at the first bridge you come to and continue along a path reserved for pedestrians and cyclists along the River Artia. This will take you to the car park (S/E).