Lacs et Pic d’Ayous hike

Be prepared for a great day, taking in the Lacs d’Ayous and the incredible Pic d’Ayous.

This is a popular hike, so you’ll likely start from the lower car park at Bious-Omettes (where the Pic du Midi d’Ossau is already visible). From here, pick one of the tracks which run up parallel along the slope to the left of the road. You will notice some red and white markings: this is the GR10, the famous long-distance path that runs the length of the French Pyrenees.

You will soon be back on the road. Follow it to the left to reach the upper car park at the Lac de Bious-Artigues, which usually fills up early in the morning.

Follow the GR10 along the left (east) side of the lake. This is a good track, which climbs gently along the forest’s edge and then into the forest. After a bridge, it steepens significantly until it reaches a gate. Contour the gate to the left and you will soon reach a fork, at roughly 5052ft.

Note that the main track crosses the bridge to your left: this is the return path, but to make the path more interesting we take a different route up.

For now, stay on the GR10 and follow the trail to the right which will take you up through a beautiful forest. The going is a bit steep in places, but the trail is well-defined and rather easy-going.

Around 5577ft you will head out of the forest for about 656ft or so. Keep walking straight uphill along the trail, which runs into a small piece of woodland before emerging again on the open ground – for good this time (ca. 5741ft). The views open and it is now a gentle ascent up to the Lac Roumassot (6053ft).

The trail then climbs steeply along a beautiful waterfall before the ground levels again. You will soon have the small Lac du Miey in sight, and in another few minutes, you will reach the Lac Gentau (ca. 6070ft), with the Refuge d’Ayous visible at the end of the lake.

After a break at the lake, head back on the trail and check the directions on the signpost. If you do not want to climb the Pic d’Ayous, head straight for the Refuge and find our explanations further along in this text.

We suggest you take the path on the right and head to the Pic d’Ayous and some spectacular views! The Pic d’Ayous is the highest point of the ridge which stands to your right, and is uniquely made of red sandstone, which makes it all the more recognisable among the other surrounding ridges.

This path up to the Col d’Ayous is among a curious colour mix composed of deep green grass, red rocks and (hopefully!) blue sky. A mere 30/40 minutes later should see you at the Col d’Ayous (7152ft) where an incredible vista awaits to the west and north-west, with a good deal of the most westerly +6562ft peaks of the Pyrenees visible, including the Pic d’Anie (8215ft). To the north, the Pic de Sesques (also called L’Escarpu, 8550ft) stands behind a fine ridge. Looking back to the east, you can admire the Pic du Midi d’Ossau in all its splendour, with other ridges further east.

At the Col you will leave the GR10, instead going right and picking the upper, unmarked path which follows the ridgeline to your right. It first heads up on the grassy shoulder before skirting around the minor top to its left (NW). Contour the latter without hardly gaining any more height, then drop down a few metres to reach an obvious path which runs parallel just below. Keep contouring the minor top until you will see a gap/col. Carefully take the last steps to the col as the path is a bit eroded for a few metres. Once at the col, embrace some great views over the lakes before the last hike up the grassy slope to the top of the Pic d’Ayous (7507ft). The summit is marked with a small cairn and offers a breathtaking 360° vista, with the mighty Pic du Midi d’Ossau being the only close summit to bar the views. Countless peaks and ridges can be admired, especially to the S, where several ridges align beyond the Spanish border.

Retrace your steps to the Col d’Ayous via the same route and start the descent back on the GR10 eastbound to the lakes. Around the 6791ft contour, leave the GR10 and veer right on the obvious path which will lead you to the Refuge d’Ayous.

The views over the lake and the Pic du Midi d’Ossau from the refuge are stunning. Now head for the trail that rises steeply on the other side of the refuge. This is the last real bit of ascent and only takes a few minutes. The unmarked trail continues along a string of tiny lakes before gently rising to reach the Lac Bersau, nestled beneath a fine rocky ridge dominated by the Pic de la Hourquette (7822ft). Follow the path that goes on the left (east side) of the lake. Soon the trails veers to reach a small gap just over 6890ft.

In front of you stands the impressive Pic de Castérau (7306ft), with its tiny lake below to its right. Head down the trail which zigzags along the slope to reach the other obvious trail below. Once in the hollow, silently head for Lac Castérau, you may spot some marmots to the right of the trail!

As you get near the lake, you will probably notice water has dug a few sinkholes in the area, with a stream even disappearing in one of them (to the right). The last of the lakes, Lac Castérau lies underneath the impressive cliffs of the eponymous peak, and will offer some beautiful reflections of the Pic du Midi d’Ossau.

Walk past the lake on the obvious trail, which then climbs for a few metres. This is the point where the real descent starts, along the steep, winding, slightly tough-going, rocky trail. The whole valley opens before you, with the same monster peak still overlooking the whole scenery. The trail reaches a small sheepfold (Cabanes de la Hosse) and a gravel track after a while. Follow the track to the left just for a few metres and then pick the trail to your right; it is marked in red and white (GR108) and can be followed all the way down.

The trail leads you down to a footbridge (it forks at one point, but the two paths meet again before the bridge). Cross the bridge and follow the path along the right bank of the river. It is now a gentle stroll down along the valley. The scenery is less impressive than on the higher ground, but is still beautiful, with the river even digging a gorge and forming a waterfall at some point.

After a last short bit of descent, you will reach a large plain where you cross a bridge, after which you rejoin the gravel track you came up on again. Follow this path down through the forest to the beginning of the walk, retracing your steps back to the car park.