Paybou Chasm circular loop via Calihourc and the Sentier de Gatès

Access: from Saint-Pé-de-Bigorre, cross the Gave de Pau at the bridge in the Le Bout-du-Pont neighbourhood.
Follow the signs for ‘Monastère de Bethléem’ until you reach a small road on the right signposted ‘Sep’. Take this road, then follow the track for a few hundred metres until you reach a pumping station. Park in the adjacent car park.

(S/E) At the corner of the station’s fence, on the river side, take the path which descends steeply towards the Génie Braque. Cross the footbridge and climb up the opposite slope to the site of a former Second World War youth work camp, the old Castets clearing.
There are several ruins here (low walls, slabs, a brick chimney and a ruined barn). Today, the site is often used as a camping area by Scouts in the summer. Numerous paths make it difficult to reach the ruined barn shown on the map, not far from the “Grotte de Castets” marker. A good landmark is the bearing to the barn from the river crossing: 165°, following several paths through the undergrowth, which are more complex than the dotted line on the map.

Leave the ruined barn on your left and continue straight on, climbing slightly until you reach the far end of the clearing (a wooden Scout structure for their flagpoles often stands majestically here). The path is no longer marked on the IGN map but can still be found on OpenStreetMap.

(1) After a short, very steep climb, just behind a tree at stone marker No. 193, leave the path which descends straight back down into the valley and turn right at a right angle, heading uphill towards the west (towards Coumo Lio).
NB: numerous stone markers (white and red) dot the massif in this way; they demarcate the indivisible State-owned Forest of Saint-Pé. This is the only one visible along the entire route.

The path climbs gently; it is well-defined, fairly wide but unmarked. However, quite soon you will spot a few blue spray-painted marks on the trees, mainly on the right-hand side of the path. Continue along this old mule track, which is often bordered by a low dry-stone retaining wall on the right.

(2) 310 m after marker No. 193, you’ll reach a junction that’s not very visible but marked with the letter ‘L’ (indicating a left turn), painted in blue on a tree to the right of the path.
Turn left – practically retracing your steps – onto a path which very quickly becomes clearly marked and signposted in blue.
Walk just a few dozen metres on level ground and, at a junction marked by a fairly low cairn made of two large stones, take the path on your right which leads into the forest and up the slope of the Sarrat dets Castets.
From here, the path is particularly narrow and very poorly marked.

Although there are no traditional markings, you will still find ‘logging trail markings’ (see Practical Information below) almost all the way to point 8.
260 m after point 3, you’ll also start to come across occasional markings, mostly in red paint, or sometimes orange, or occasionally with red strips of fabric.

Continue the ascent, keeping well on the ridge (the Sarrat).
In the distance to the left, there are several wonderful views of the Soum des Toupiettes, the summit of the Araü mountain.

(3) Just before the 946-metre point, cross a 5-metre ledge (R5), keeping slightly to the right of the ridge where you’ll need to use your hands. It is not exposed.
Shortly afterwards, the path veers slightly to the left of the ridge.

(4) At the Couhéssadéres (confessionals) site in Calihourc (a dark, unpleasant spot; a den; an ugly, poorly situated wood) (NNMSC = name not shown on maps), take a short photo break then continue along the ridge, through a young beech forest and undergrowth that is becoming increasingly sparse.

(5) Reach the pretty, level clearing at Couret Beroy (NNMSC). A fine tree stands in the middle of it. The logging trail markings, or red and orange markings, come to an end.
This is the junction with the path known as the Sentier des Tachouères (NNMSC), which links the Aülhet mountain pastures with those of Bat dé Haü. The markings are yellow.
The path leaves the clearing to the west and continues through an ancient beech forest. First, leave the first valley, the Lio, on your right; it has several tributaries, all very ravine-like.
Pass beneath the Soum des Briolles (or Soum de Mesplé, NNMSC) on the left, with its gentle slopes that lead down to the path you are following. At the same time, leave the first sarrat, the Abédat (NNMSC), on your right.
You will also pass the Coumat de la Lit and reach the Sarrat de la Garro (NNMSC), clearly visible on the right.

Still deep in the forest, shortly after the ridge, leave the path to your right and descend onto the crest. As soon as possible after the rocky outcrops, turn right along the cliff face, down a very, very steep slope.
NB: without a GPS, from here to point 8 and La Génie Braque, finding the trail may prove difficult...

(6) A few dozen metres further on, you will find the entrance to the Gouffre de la Tranchée in a crevice. The entrance is nestled between two elongated rock formations, as if in a trench, hence its name.
This is the second entrance (or exit) to the Paybou-Tranchée network on the left-hand slope of the sarrat (to the west), which descends towards La Génie Braque.

On your way back, head in a northerly direction (azimuth 225°).

(7) Reach the Gouffre de la Garro, also known as the Gouffre de la Waterfall.
It is easier to locate using a GPS. A large, fairly short beech tree, about 40 cm in diameter, has fallen and is covering the mouth of the 13-metre-deep entrance shaft (see photo No. 130704).

Continue the descent for just a few tens of metres in elevation, whilst heading northwards. Avoid several rocky outcrops by keeping them on your right.
A cairn-marked path may sometimes be visible, leading to the chasm.
Warning! You must use a GPS to locate this chasm, as it must be approached from the bottom rather than the top of the slope (risk of slipping and falling into the chasm).
''NB: When looking up the slope from the bottom, the location of the chasm can be identified more easily by the presence of a striking beech tree with a large branch extending from its base and rising steeply vertically to form a U-shape (see photo No. 130700).
''
(8) Reach the entrance to the chasm. “It’s enormous! The diameter is around ten metres. The entrance shaft is 45 m deep. Standing on its edge, you feel as though you’re being sucked into the void. Caution: danger!
The dimensions of the cave itself are impressive: 1,400 metres in length and a vertical drop of 181 metres!”

Continue the route by heading down the slope towards the north-west, with the Génie Braque as the junction point, at the minimum distance between it and the Sentier de Gatès (NNMSC; path towards Bat dé Hau, shown in black and purple dotted lines on the IGN map), at elevation 830. The azimuth is 290°. Take care on the descent; there are several rocky outcrops to avoid, and there has already been an accident in this area in the past.
Crossing the Génie presents no difficulty (except possibly during high water following a storm).

Quickly rejoin the Sentier de Gatès. Turn right onto this path, which is very well marked and signposted in yellow.
This descent may seem quite gentle compared to the route taken so far.

At the 466-metre mark, leave the path and join a section of well-tarmacked road. Continue along this road for a few dozen metres until you reach the car park (start/finish).

As is often the case, I’m taking you along little-known, unmarked paths that are even rather hostile to walkers, except for the long section of the return journey.
All these ancient sites – and sometimes the paths themselves – are briefly described by Abbé B. Abadie in his 1969 book *Le Sanglier du Picharrot*.

Warning!
This walk takes place in the heart of the countryside in a rather challenging environment: steep slopes, rocky outcrops, cliffs, thorny undergrowth, sometimes a complete lack of signposting, and at times even no path at all… This is why it is reserved for seasoned, fit walkers with a good sense of direction. A GPS device may also prove very useful.
I have classified this hike, undertaken when there is no snow, as ‘Difficult’ due to the challenges described above and, in particular, the numerous sections off the beaten track and without signposting.

Forest clear-cutting markings
(Non-standardised term)
This is a very old practice used by hunters, who mark a route by generally cutting young trees with a diameter of 1 to 5 cm, at a height of around 1.5 m. Here in Très-Croutz, these are most often box trees. You may also find, in addition, large notches made with a machete in larger trunks.
This technique allows hunters or walkers to follow the markings by sight.
Its advantage lies in its simplicity and its modest environmental impact compared to paint. Furthermore, it is much more durable.
The downside is that walkers are not very used to this type of marking and wayfinding, and that junctions of paths marked in this way can lead you somewhere other than your intended destination...

Water sources
You should be wary of any other springs or water sources you come across, as drinking water in the mountains is not guaranteed to be safe...
Set off with at least 1.5 litres of water per person.

Places to stop and take shelter
In the event of heavy rain or thunderstorms, there is no proper shelter along the route.
If necessary, you can reach the Refuge d’Aülhet, a quarter of an hour’s walk from (7) (part of it is open all year round to walkers).
There are also a few makeshift shelters, such as low walls or rock faces, dotted here and there.

Equipment
Bring the usual equipment for a mid-mountain hike (hiking boots, suitable clothing, rainwear, water, food, survival blanket, knife, compass, map, whistle, GPS, etc.).

Traffic
In spring and summer, you may come across the occasional hiker or shepherd between (7) and (S/E). Very rarely elsewhere during the warmer months and no one in winter.

Spelling of place names
Several place names have different spellings: in Occitan, Bigourdan, Gascon, Frenchified Gascon, French, IGN-style variations, etc.

The remarkable site of Calihourc, with its immense sharp limestone pavement – light grey limestone rocks battered by erosion, shaped like confessionals – celebrated and photographed by Abbé Abadie in his book *Le Sanglier du Picharrot*. Shrubbery has overgrown this site for over a century.
The place is truly magical...

(8) The Gouffre de Paybou
Legend attributes it to the unfortunate Paybou around 1910, whose load of firewood was swallowed up by the chasm’s vast maw and is said to have slid all the way down to the Génie Braque… First reported by the shepherd JP. Mousseigne in the 1940s, then explored on 29 August 1944 with E. Ross, J. Prat, M. Ponnau and M. Blanchet. Exploration continued upstream with the BETAP (later SSPPO) at Easter 1950 and 1951. In 1952, President René Lepront led the BETAP expedition, which ascended a new 12-metre waterfall to reach +83 metres in 1953. It was not until 1982, during the cave’s topographical survey, that a further 200 metres were added, bringing the depth to +112 metres (Jacquet – A. Dole, GSHP). In 1984, the GSHP (Vignau, JP.Douat) explored a skylight passage in the -60 m chamber, which was re-explored and surveyed over 150 m in 2007 by Ph.Grard, M.Rasse and T.Braccini of the Club des AQUA. In 2016, a fissure discovered (“la Tranchée”) by JC.Mengelle (GSHP) was widened by this club. In 2017, the connection with Paybou was established; tins from the BETAP dating from 1953 were discovered... (JC. Mengelle, S & P. Degouve, A. Massuyeau, M. Creste, J. Sanchez).
In 2022, the GSHP completed the feats of its predecessors by carrying out the first Paybou–Tranchée and Tranchée–Paybou crossings using two teams travelling in opposite directions, meeting underground...

Flora and fauna
The vegetation of this mountain range reflects the severity of soil drought caused by the terrain and the highly permeable nature of the subsoil, though this is offset by very high rainfall and cloud cover: boxwood, beech, lime and hazel are ubiquitous… This is why the wooded slopes are very damp and can sometimes be very slippery. (source: Saint-Pé Tourist Office).
A large part of the walk takes place within the Saint-Pé “Integral Biological Reserve”, covering 1,010 ha of the 2,588 ha of the undivided forest of Saint-Pé (see the ONF.fr1 and Natura 2000 websites).
Regarding the rationale for leaving “dead” trees in place, there are some interesting articles on the Wikipedia pages on Deadwood and List of ancient primeval forests.

With a bit of luck, you may also come across a wealth of wildlife. In particular, wild boar, roe deer, chamois, and occasionally mouflon at the Pic de Miquéu, as well as countless birds and various insects, and occasionally amphibians (frogs, toads, salamanders).

You can enhance the suggested full route by:
- a detour to the Aülhet mountain hut (1,160 m); allow an extra 30 minutes there and back,
- a visit to several caves, chasms and karstic caves, most of which are not marked on the IGN map (1,600 cavities are recorded in the massif), provided you have the necessary skills and equipment!

A bit of history
The Saint-Pé forest is also known as the Très-Croutz forest (or Très-Crouts, Tres Croutz, Tres Crouts or Tres Crots).
The origin of the name ‘Très-Croutz’ is thought to derive from the ‘Trois Croix’ (very croutz in Bigourdan/Gascon) carved into the stone at a place known as ‘la Toue’, right in the heart of the massif, at an altitude of around 1,400 metres.
The Three Crosses bear witness to age-old pastoral conflicts between Asson, Salles and Saint-Pé-de-Bigorre.
In 1569, the Protestants from Béarn in the Asson valley decided to attack the Bigourdans of the Estrèms de Salles, with whom they were disputing the Azun and Maumula mountains. The 1,500 men were ordered to lay waste to the village of Salles and seize all the livestock from Vergoun. But the battle was won by the Bigourdans. These conflicts became so serious that the King’s army had to be called in. It was impossible for the Bishop of Tarbes to restore harmony. Source: Abbé B. Abadie, *Le Sanglier du Picharrot*, published by Marrimpoey Jeune.
At a place known as “Très-Croutz”, the bishoprics of Tarbes, Lescar and Oloron converged on this mountain.
Today, all that remains are three crosses carved into a rock, along with the inscription ‘1716’. They can be found on the IGN map between the ‘u’ and the ‘e’ of ‘La Toue’, south-west of Miquéu.

Nearby attractions
- The town of Lourdes and the Marian shrine;
- The Batsurguère Valley;
- The village of Saint-Pé-de-Bigorre, the village itself, its cultural heritage, its events, the Très-Croutz forest and the Pibeste-Aoulhet regional nature reserve, water sports;
- The story behind the reserve’s new signposting in autumn 2014;
- The Gaves Valley

Find out more...
- It is well worth consulting the website and publications of the Pibeste-Aoulhet Regional Nature Reserve. The most notable of these is the “reserve guidebook”, packed with information, routes and anecdotes!
- The Saint-Pé Tourist Office also publishes numerous brochures and detailed hiking itineraries. One of the brochures may be of interest for discovering the massif’s flora and fauna: the ‘Karst Trail’ brochure, even though it does not cover this particular hike.
- The former Peyras farm, now the Monastery of Bethlehem.
- You can immerse yourself in local literature:
Abbé B. Abadie, *Le Sanglier du Picharrot*, published by Marrimpoey Jeune,
Jacques-Emile Mengelle, *Bigorre de mon enfance*,
Jean-Claude Mengelle, *Le solitaire de la Gargante*.