This country tour, to the east of the Regional Natural Park of the Ariège Pyrenees, in the heart of the Biros valley, of incredible beauty, will introduce hikers to the history of this mining valley, from which zinc and lead have been extracted for over a century. Itinerant hike, it opens the doors to beautiful days on steep trails, offering exceptional panoramas on the summits. This fully marked loop imprinted on pastoral, mule and mining paths, in a mid-mountain setting. For the more adventurous, it is possible without too much difficulty to climb the Pic du Crabère, which culminates at 2m.

The Biros tour in a few words

  • Total distance: 53 km
  • Loop in 4 days (about 15 hours of walking)
  • Cumulative positive elevation: 3m
  • Cumulative negative elevation: 2 970m
  • Departure Arrival : Anglade parking lot in Sentein
  • Markings: Yellow and Red GR de Pays
  • Level of difficulty: Level of difficulty: 3/5. You are in good physical condition and are prepared for a multi-day hike in the mountains. Air passages. (3h20 to 6h of walking per day with positive elevations of 15 to 300m and negative elevations of 1 to 100m)

Favorable period

Given the snow cover and the guarding periods of the Araing refuge, it is advisable to do this trek between the months of June and September.

Useful addresses :

  • FFRike:  - 01 44 89 93 93 -
  • FFRandonnée Ariège: - 05 34 09 02 09
  • Le site created by the hosts to prepare your stay
  • IGN maps of the valley 1/250000: Aspet 1947 OT and Aulus-les-bains 2048 OT
  • Itinerary described in the GR10 topo guide "Crossing the Pyrenees - Pyrenees Ariègeoises and tour of Biros" - FFRP edition

The steps

Stage 1: Anglade car park (Sentein) - Refuge d'Araing

  • Duration: 3h30
  • Elevation +: 1100 m

In this stage, we discover superb beech forests as well as the narrow and deep valley of the Isard. At an altitude of more than 1300m, the chapel of the Izard is revealed on the right. What astonishment to see a chapel at such a high altitude! Every year on August 5, there is still a pilgrimage in honor of Our Lady of the Snows. It must be said that the chapel has something mystical about it ... and that many miracles have followed one another since the beginning of the 20e century…

Higher up, the Pic de Crabère and the Araing circus overlook the valley. The circus is grandiose and unforgettable, as are the landscapes. Allow 3 hours more for the climb to the top of Crabère.

Picnic or overnight break possible in the open part of the chapel of the Izard.

Stage 2: Refuge d'Araing - Gîte d'Eylie

  • Duration: 3h20
  • Elevation +: 300 m
  • Elevation -: 1230 m

This high-altitude stage crosses a pass at an altitude of 2221m, then slowly descends to the hamlet of Eylie. It is a page of history that is revealed in the descent when you discover the mines of Bentaillou. The flagship of the mining industry in the XNUMXth centurye and XXe century, the Bentaillou mines, located at an altitude of 1900m, are a place of zinc and silver lead extraction.

In 1907, the Bentaillou mine employed more than 500 people! The men and their families having come to settle in Biros, the valley is repopulated, and at the school of Sentein, we welcome more than 200 pupils.

From the end of the First World War, the decline was announced. The depletion of minerals, the operating costs due to the altitude of the deposits, the rural exodus will be the reason for these operations ...

The hamlet of Eylie appears at the end of the route, these perfectly well preserved small barns in the heart of this unspoiled and wild valley.

Stage 3: Gîte d'Eylie - Relais montagnard de Bonac-Irazein

  • Duration: 5 hours
  • Elevation +: 740 m
  • Elevation -: 950 m

The stage offers a balcony crossing on a path of the guards of great beauty: passages in meadows strewn with junipers, strolling in the wood of Laspé, 360 ° point of view as at Tuc de Pâle at 1767m altitude … The trail is varied and the beeches and steep corridors of the Laspé cirque are reminiscent of certain corners of Spain.

Stage 4: Relais montagnard de Bonac-IRAZEIN - Anglade car park

  • Duration: 6h15
  • Elevation +: 900 m
  • Elevation -: 790 m

Mid-mountain stage in a splendid setting where you can discover all of Biros with a breathtaking panorama, which also allows you to visualize all the stages accomplished. The various passes such as the Croix, Hérédech or Blazy pass offer a beautiful view.

A beautiful route, which allows you to learn gently to the practice of hiking in the Pyrenees, taking advantage of the magnificent landscapes of Ariège and astonishing discoveries linked to the mining history of the region […] Read the adventure story




What equipment to take in your bag?

If you sleep in accommodation on the course, you won't need much in your backpack! Here is a list that can help you prepare for your roaming:

Chaussures de randonnée
  • 40L backpack (and its over-bag to protect in the event of a downpour)
  • Gourd, knife, flashlight, compass, garbage bag, cap, sunglasses
  • Windbreaker jacket (or a k-way)
  • Couchae bag or silk bag (to sleep in a refuge because the sheets are not provided, the blankets are however)
  • Polar
  • Hat, light gloves
  • Hiking boots
  • Small towel: ideally in microfiber, it takes up less space and it dries quickly!
  • First aid kit: painkillers, dressings, disinfectant wipes, arnica balm, sunscreen, mosquito repellent, survival blanket ...

further information

Accommodation: Stopover gites and refuge

  • Each accommodation provider offers free management, half-board, full-board packages with picnic.
  • Reservation required at each accommodation
  • Bivouac possible near accommodation or on the route.

To get to Sentein other than with your vehicle

It is possible to take the train from Toulouse to Boussens, then the SNCF bus from Boussens to Saint Girons. More information on: You can then opt for the bus, taxi or hitchhike to go up in the valley.

More details on bus schedules from Saint Girons at theCouserans tourist office.

7-seater taxis, 7 days a week - Castillon: 7 06 73 51 75 / Saint Girons: 40 06 82 85 32

Do you like roaming hiking? So find out ...