This is probably the easiest and less compromised (and therefore less exciting!) route to reach the summit of Soum Couy. It goes along the runways of the ski resort placed at la Pierre-Saint Martin, and therefore is FORBIDDEN during the ski season
(unless you want to get into serious trouble getting run over by a skier, which would guarantee serious damage for both of you!). But... it's an easy hike, goes up easily and fast to the top and guarantees wonderful sights, especially when getting close to the summit.
Arette-La Pierre St.Martin
BY ROAD: Via Isaba (Navarra - Spain):
For the spanish approach you will have to get to Arette-La Pierre St.Martin from Pamplona or Huesca, the biggest closer cities. Follow the road linking both of them (N-240) until the crossing of Venta Carrica. This is a crossing about (will check) sixty kilometers from Pamplona, where you can find a petrol station and the beginning of the road to Sigüés / Salvatierra de Esca / Roncal. Follow this road (NA-137) for thirty kilometers, until you get to Isaba. After Isaba keep going north (NA-1370) towards France (follow signposts "Francia"). It is a twentyfive kilometers drive, mainly on the valley floor at first and afterwards by the southern slopes of Lakora. You will find the small mountain restaurant of Juan Pito and the Belagua Mountain Hut, actually abandoned but created and administered for many years by the Club Deportivo Navarra. The ski resort is placed about two kilometers after the border.
Via Arette (France):
Start from Biarritz, driving to St Jean-pied-de-port, Oloron Ste-Marie and Arette. From this last village you will have to drive up the col de la Pierre-St.Martin to reach the ski resort of Arette-La Pierre St.Martin
From the spanish side, the only chance to get somewhere near Soum Couy is via the buses of "La Tafallesa", starting at Pamplona and leading you to Uztarroz (in the Roncal valley). It's either that or joining an organized winter day trip to the ski resort of Arette (almost any travel agent in Pamplona might inform you about this kind of trip).
The closest airports are those placed at Pamplona (Spain) and Biarritz (France)
There are two basic options for this hike, and this page describes our circular track when we climbed Soum Couy. Nevertheless, it could also be done the other way round (or even up and down by the same route). It's your choice!
Start walking along the runway that goes down from the buildings towards the forest (grossly north-northeast). Just follow it all the way long until you reach the lower end of the chairlift. That will be the place to turn right (east) and start climbing the slopes of Soum Couy, following another chairlift through the pine forest. That way you will find yourself on the long summit slope of the mountain, just turn right and keep going up (and south!) towards the summit. If you are lucky enough to have a sunny day, the summit of the Pic d'Anie will appear behind Soum Couy as you approach the higher areas of the mountain.
A little bit before the summit you will find the upper station of the chairlift. Keep that spot in mind, for it marks the beginning of the runway known as "Boulevard des Pyrenées". The "Boulevard" leads west and offers an alternative way down that will lead you to the Cabanes (huts) de Pescamou, under the Pic d'Arlas, and finally to the central area of the ski resort (that is: to the car park).
There's not much to be said in this section... Good walkers can get to the highest station of the chairlift without any significant trouble, especially in summer time, but walking poles are always useful for the downhill return and might be helpful in the upper slopes of Soum Couy. Apart from that, take all necessary gear and clothing according to the weather predictions, food, and so on...