By car:
Cross the border at Dantxarinea, then follow the N-121-B to the Col d'Otxondo. About 600m after this pass, turn right at a picnic area and take the NA-4453 for 11km to the Etxebertzeko Borda sign, then right down to the restaurant. Park on the pediment ("wall on the left").
On foot:
(S/E) Follow the signs for "Molino del infierno" or "Infernuko erreta", the path runs more or less overhanging the river.
(1) Ignore a wooden footbridge on the left (to be used later) and continue West for a short round trip to the well-restored mill. During the many wars, it continued to turn to supply the surrounding population.
(2) Retrace your steps.
(1) Back at the wooden footbridge, cross the stream (careful no handrails) and take the path up into the forest. Leaving a start on the right, you come to the Barrentxea farmhouse, which you go round to the left, staying on this side of the track until you come to an iron gate, where you cross the fence to rejoin the track, which continues to rise.
(3) At a right-hand bend in the track, leave it and turn left onto a path that runs deep into the forest.
(4) Reach a track (the summit of Zapitor is 100m away) and take it downhill to the left. Pass a sheepfold with a red corrugated iron roof.
(5) 250m further on, at a three-way junction, turn right onto the track that descends to the road. Follow the road to the right for about 1km.
(6) At the power lines with iron pylons and cement poles, take the track on the right. 700m further on, leave the track on the left, which leads down to the Zapitorko farm and continue on the track for about 250m.
(7) Leave the track that continues to the Iturraldeko farm and turn right up the hill. (unknown, for 700m on the IGN map of Spain, but present on the OpenStreetMap hiking map). Reach a small pass with a crossroads. Turn left (North-West) and climb to the summit of Mendiabo.
(8) From the summit, return to the small pass and the trail junction and take the one descending to the North-East.
(3) Rejoin the trail from the outset and continue left on the track down to the Barrentxa farmhouse, then to the stream, which you cross again.
(1) Turn right to reach the restaurant on the outward path (S/E).