Park near the Trinquet in the centre of the village of Larrau. There is a small square behind the sports hall where you can park a few cars.
(S/E) Start from the fountain in the middle of the square. A sign indicates the direction of Col Erroimendi. Head between two houses (south-west). Follow this well-marked path, which climbs steeply. Turn left at thefirst fork. The path is then open and continues to climb southwards.
(1) You will come to a track, which you cross. Enter the forest heading southwest, following numerous hairpin bends and turning right at the fork.
(2) Join a wide track and turn right (due west).
Very soon, a path branches off to your left, climbing again into the forest, heading due west. Numerous hairpin bends in the forest, heading due west, lead you to a clearing.
(3) Arrive at the restored Chapel of Saint Joseph. The path becomes a track through the forest heading due west. Arrive at a new clearing with high-altitude summer pastures. The track then heads due south.
(4) Soon, a scrap metal cross (Croix d'Erroymendi) appears on our left.
(5) Very soon you will come to another, wider track. Turn right, heading due south-west. The pass is in sight.
(6) Arrive at the Col d'Erroymendi (1361 m). It's time for a snack from your rucksack. The return journey is along the same route in the opposite direction (otherwise it's the road to Larrau).
From this pass, in good weather, you can go to Pic d'Orhy (2017 m) by following the sheep tracks (south-west).