From Irun, head for the Aiako Harria Nature Park; the road winds up to the pass, with parking along the road that descends after the pass.
(S/E) Go down to the bottom of the car park and take the path supporting the GR®11 which heads South-West, into the forest opposite after crossing the road.
(1) At the crossroads, turn right, staying on the GR®11.
(2) At the next left-hand hairpin, turn right along the Canal Domiko.
(3) Continue straight ahead on the PR®- GI-1010 Aiako Harriko tontorrei bira (Tour of the Three Crowns summits in Basque). This also follows the Canal Domiko to the lake, passing beneath the Aialde restaurant, whose terrace overlooks the lake.
(4) At the hairpin bend in the road, turn left to the East onto PR®-NA-11 Sant Anton Domiko.
(5) At the entrance to the Lake Endara dam, turn left, heading North, on the cemented GR®-11.
(2) Turn right, still on the GR®-11. Return to the start via the path taken to reach the car park (S/E).