From Saint-Jean-de-Luz (exit 3 of the A63 motorway), follow the D918 towards Ascain and Saint-Pée-sur-Nivelle. Head towards the centre of Ascain. Turn left at the town hall and church square (towards Sare) and, further on, turn left towards the Roman bridge. Park in the car park on the left, where the hike starts.
(S/E) Leave the car park and turn right to go up the street. At the intersection, continue straight ahead on Route de Martzenea until you reach the cemetery.
(1) Turn right towards the church and walk along it on your right.
(2) At the corner, turn left and cross the street to pass in front of the town hall. Continue between two agricultural plots and, facing a property, turn right at the slate roof. The path runs along a hedge and leads to a road.
(3) Turn left. Take a stony path on the right. Continue through the undergrowth and turn right onto a track. At the end, continue along a narrow path. Go through a gate and turn left onto a track until you approach a house.
(4) Take a path that climbs to the right and leads to a motocross track.
(5) Turn left and climb quickly to the right after a track. The path joins a wide track.
(6) Follow it uphill, describing a large loop in the slope covered with gorse and ferns. Then enter the Vallon des Trois Fontaines and discover the summit of La Rhune. Continue along the wide path, past a cayolar (shepherd's shelter) and two beech trees. Cross a stream (plum tree and cliff) to reach an intersection (388 m).
(7) Take the path opposite and continue along a stony path uphill. Cross a stream and continue along its right bank. Pass a few rocky outcrops until you reach a shepherd's hut. Leave it on your left and continue climbing opposite until you reachthe GR®10.
(8) Continue to the right on the GR®10 until you reach the Col d'Errepausu.
(9) At the pass, take the path on the left between the trees. The final climb is exposed and steeper. Follow the switchbacks to the summit of La Rhune, avoiding cutting corners to limit erosion. Cross the railway line and you will reach the summit (905 m).
(10) After enjoying the view and the terraces (905 m), descend to Ascain via the same route you took on the way up. (S/E)