The Arbizon, 2831m, is far to be the highest peak of this region of the French Pyrenees, but it is a very well-known mountain, very excentred from the main ridge, just like the Pic du Midi, and which overlooks all the plain of the Bigorre.
It can be recognized from every viewpoint far from the Pyrenees, even from the hills of the north side of the Garonne river some 200km north ! (The Arbizon stands right from a wide depression which corresponds to the entrance of the Aure valley)
South-West Panorama (hand-made with paper photos...)
from the Montfaucon
The first know ascent took place in 1825, by the two geodesy officers Peytier & Hossard. The etymology of the word "Arbizon" is not clear and subject to numerous debates.
The arbizon is made of various minerals, but we could say that it is made mostly of loose stone of various types of schists. On the north slope it tends more to be limestone, very dark grey since full of carbon. On the North side, in few places is located a very rare mineral, the "grenats grossulaires". More informations here.
The Arbizon is a very prominent and individual mountain, despite it belongs from far to the Néouvielle group, assuming that it is linked by this chronologic list of neighbouring tops (east to west) :
Monfaucon, Aulon, Portarras, Bastan, Estibère, Madamète...
The peak overlooks the Aure valley, as it forms the cul-de-sac of this ridge as a proud promontory...
Or almost, since the Arbizon has a small brother, the "Petit Arbizon", 2737m, whose traverse to the big Arbizon make a fine ridge walk.
It is interesting to mention that the Arbizon delimitates north the separation of 2 main waters in South West of France: all streams located West flow into the Adour, ending in the Basque Country, while all streams East end into the Garonne, which ends some 400km further north under La Rochelle. In other words, in theory you can walk from any point of the Gascony without crossing any river and you'll get to the Arbizon in all cases.
From the Arbizon, the panorama is extraordinary, with an exceptionnal range of peaks, which all seem extremely distant. To be fully appreciated, the Arbizon must be climbed with very clear sky and weather. Especially the views extending West from the Néouvielle region to the Monte Perdido, and the Bachimala south are very nice, making a fine panorama to the highest peaks of the area, illuminated in the direction of the morning sun. Looking East, it is less spectacular since overlooking the low mountains of the low Luchonnais. But the Ariège is visible in the very far skyline.
The Arbizon (middle) seen from the neighborhood of Marmande, some 200km further North
Over a sea of clouds
It all depends from where you want to climb the Arbizon.
Most of the people start from the Aure valley, which you reach from Lannemezan, located on the A64 motorway which runs on the north side of the Pyrenees.
Some other might prefer a more original ascent from Payolle, on top of the Campan valley, which is also reacheable from the A64, but from Tarbes (preferably if you come from West).
From Spain, cross the tunnel of Bielsa to reach the Aure Valley.
Note that there is a very tiny road going via a high pass, the Hourquette d'Ancizan, from Ancizan to Payolle and which makes a very good way to approach the Arbizon, with many possible starting points.
Going there by public transports, you can easily get to Lannemezan by train, and get into the Valley d'Aure by bus. There are good chances that the Payolle ski ressort is served by bus, but good chances that it is only in winter...
There are many routes to reach the Arbiron. All of them are very steep and involve a high level difference. Go preferable to the Arbizon without snow, unless you really know what you are doing.
from the Hourquette d'Ancizan
from the South
* The most common is from Aulon from a place commonly known as the "Granges de Lurgues" (Lurgues barns). Climb north into a very steep and monotonous slope of schist screes until the end... beware not to slip in one or two places, few easy scrambles required here and there.
* Another quite famous route is from the Hourquette d'Ancizan, via the North face of the Arbizon, which is said to me much more spectacular, and a bit more difficult, with easy rock-climbing. Climb first to the Coume de la Maoubé, and the corridor via the Petit Arbizon, which you can additionally climb.
* Another similar approach from Payolle goes via the Lake of Arrou, but extending the walk approach. The Monfaucon can be climbed additionally.
If you plan to ascend the arbizon in winter make sure the road to the Hourquette d'Ancizan is accessible
If you go with snowshoes starting from the Payolle ski resort, beware to be discret enough, unless starting very early. Few people reported to get in trouble just because they crossed the ski area with show equipement, which suppsed they should have bought a day-ticket...
If you come from Spain, the tunnel is closed before 8am, which is problematic if you plan an early start. Closure at 20pm, don't be blocked in France too :)
From the Pic d'Aret
Wild-camping is allowed everywhere in this area of the Pyrenees which does not belong to any National Park neither Natural Reserve.
There are several official campsites in the Aure Valley, as well as accomodations :
(go to the "hébergements" category, the Tourist Information of the Valley d'Aure didn't even mind to translate the site, which is a shame...)
One accommodation is worth mention for large groups of people: La Filature (former spinning mill), in Ancizan, with further information here and here (French). Prices can go as low as 10€ for groups over 10 people. A separate apartment is available too but rates may vary depending on the charges being shared with others or not.