Get to a Pyrenean valley with a known territory and watch the cliffs from below

Work out that it is not after the marrow — it swallows bone whole, up to twenty centimetres at a time

Look for the bone-dropping sites, where the same rock slabs are used again and again

Learn the silhouette: the long wedge tail and narrow wings separate it from griffon at a great distance

Find out where the Cantabrian birds came from and why Aragon supplied them

The quebrantahuesos — bone-breaker — is the only bird in the world that lives almost entirely on bone. It does not put its head into a carcass like other vultures; it waits until the carnivores, crows and griffons have taken everything soft, then takes the skeleton. It swallows pieces up to twenty centimetres whole, and carries larger bones to height and drops them on rock to shatter them. About 75% of its diet is the bones of wild and domestic ungulates. The Pyrenees hold the core European population, and birds from Huesca have been used to reintroduce it to the Cantabrian range.

The Bearded Vulture: The Bird That Eats Bones

Walk in to the Sarradets refuge the normal way, from the col des Tentes over the port de Boucharo on the border and round under the cliffs, rather than up the échelle des Sarradets out of the cirque, which is the steep route — and finish over the col des Sarradets at 2,589 m with the Brèche directly above you

Walk through the gap at about 2,807 m and pace its width — forty metres, with the France-Spain frontier running along the whole of it, so there is no single point where you cross — then look up at the sixty-odd metres of wall still standing above your head

From the Spanish lip of the Brèche, look south into the Sobrarbe in Huesca and work out the three things this gap opens the way to: the Ordesa canyon dropping away below, the Mont Perdu off to the east and the Taillon on your right hand

On the way back down, look across to the Fausse Brèche and find the abri Gaurier under the pic Bazillac — the cave in the cliff that the abbé Ludovic Gaurier fitted out in 1906 and the Club alpin français improved in 1911, and the only shelter up here until the refuge was built

The Brèche de Roland is a gap 40 m wide and about 70 m deep cut clean through the rim of the cirque of Gavarnie, and the border between France and Spain runs along its whole width — the Pyrenees National Park on one side, Ordesa y Monte Perdido in Aragon on the other. The legend has Charlemagne's nephew Roland opening it after Roncevaux, not by cutting the rock but by trying to destroy his sword Durandal against it; when the blade would not break he threw it, and the story says it ended up in a cliff at Rocamadour, three hundred kilometres away. Roncevaux is a hundred kilometres west of here, which makes the name doubly poetic. The usual way up is from the Sarradets refuge at 2,587 m, and old snow sits in the gap well into the summer.

The Brèche de Roland: Roland's Sword Cut in the Cirque Wall

Walk the valley-floor path from Gavarnie village to the Hôtel du Cirque at about 1,570 m, the building at the foot of the wall that marks the end of the easy ground — on foot, or on a horse or donkey hired in the village in season — and note where the second route into the cirque comes down, the Échelle des Sarradets on the rim above you

Stand under the Grande Cascade, 422 m from lip to foot and set a little east of the centre of the wall, and follow the water it makes: this is the head of the Gave de Gavarnie, which becomes the Gave de Pau and runs past Lourdes fifty kilometres north. In hard winters the cirque's falls freeze solid and are climbed on ice.

Pick the Brèche de Roland out of the rim of the cirque — a glacial notch 40 m wide and about 70 m deep at 2,805 m, which is the Spanish border across its whole width — and judge its scale against the wall around it. The legend that Roland cut it trying to break his sword after Roncevaux does not survive a map: that battle was a hundred kilometres west.

From the foot of the cirque, read the wall upward: three tiers of rock, each separated from the next by a near-level ledge, rising close to 1,500 m. Then name the rim from east to west — Petit Astazou, Pic du Marboré at 3,248 m, Pic Brulle, Pic de la Cascade, Épaule, Tour and Casque du Marboré — and find at least two of the five relic glaciers still lying under the crest between them.

The Cirque de Gavarnie is a glacial amphitheatre about six kilometres round, its walls rising in three tiers for nearly 1,500 metres from a floor at about 1,570 metres to the Pic du Marboré at 3,248. In the middle of it, a little to the east, the Grande Cascade drops 422 metres — the source of the Gave de Gavarnie, which becomes the Gave de Pau further down — and relic glaciers still sit under the crest, with the Brèche de Roland, a notch cut by a glacier, on the skyline. It has been part of the Pyrénées–Mont Perdu World Heritage Site since 1997. A level path, walkable or ridable by horse or donkey hired in the village in season, leads from Gavarnie to the foot of the cirque.

Gavarnie: The Cirque and Its 422-Metre Waterfall

Walk the Ordesa Valley, where 21km² were declared a national park by Royal Decree on 16 August 1918, up to the Cola de Caballo waterfall at its head

Walk the Faja de Pelay, the ledge path along the wall of the Ordesa canyon

Climb to the Góriz refuge, the base for Monte Perdido at 3,355m, in the park listed by UNESCO as the Pyrénées–Mont Perdu World Heritage Site in 1997

Walk the Añisclo Canyon, and look for bearded vultures and Pyrenean chamois

Ordesa was made a national park by royal decree on 16 August 1918, three weeks after Covadonga, which makes the two of them the first in Spain. The Ordesa valley is a glacial trench with vertical limestone walls a thousand metres high, and the Faja de Pelay is a ledge path running along the face of one of them. Above it Monte Perdido reaches 3,355 metres — the highest limestone massif in Europe. The park joined the French side of the range as the Pyrénées–Mont Perdu World Heritage Site in 1997.

Ordesa: The Faja de Pelay and the Cola de Caballo

Walk up the Ossoue valley from the barrage d'Ossoue on the GR 10 as far as the grottes Bellevue at about 2,400 m, and find the fork there where the path splits — right for the Petit Vignemale and the refuge, left for the glacier

Sleep at the Refuge Bayssellance at 2,651 m on the east side of the Hourquette d'Ossoue — the highest and oldest guarded refuge in the Pyrenees, built in 1899 and rebuilt in 2003, with 58 places in summer — and find the ogival stone vaulting kept from the original building

Stop at the grottes Bellevue on the GR 10 at about 2,400 m, the Russell caves you can walk to, then from the glacier look up at the higher ones and measure by eye the twenty-odd metres of ice that has gone from under them since Russell had them cut

Cross the glacier d'Ossoue — the largest glacier on the French side of the Pyrenees, 45 hectares in 2011 and down to 25 by 2022 — to the base of the pique Longue, and finish the last stretch to the top on easy rock

The Vignemale is the highest summit of the French Pyrenees at 3,298m, and the normal route crosses the Ossoue glacier from the Bellevue caves on the GR10 to the foot of the Pique Longue. Count Henry Russell made the first winter ascent on 11 February 1869 with the guides Hippolyte and Henri Passet, sixteen hours' forced march from Gavarnie, slept on the summit in a lambskin bag in August 1880, and then had seven caves cut into the mountain between 1881 and 1893 — the last, the Paradis, at 3,280m just below the top.

The Vignemale: The Highest of the French Pyrenees and Russell's Caves

Drive the eight kilometres up the dead-end valley and work out that the spa is in a cirque with no way on

Take the waters, which the Romans were already exploiting here

Work out what the 19th century did to this valley and how many people the spa supported

Walk up to the ibones above the resort, which are glacial lakes at altitude

Come in winter for the Panticosa-Los Lagos ski area on the other side of the valley

Eight kilometres up a dead-end valley from Panticosa, in a glacial cirque ringed by peaks, is a thermal spa built in the 19th century on a Roman-era exploitation of the same springs. The 19th century was its high point — the village itself is mostly buildings from that period, when Panticosa held nearly nine hundred people on the back of the spa. The waters come out of the mountain in a place where there is nothing else, and the ibones, the high glacial lakes above the resort, are a short and very steep walk further up.

Panticosa: A Roman Spa in a Glacial Cirque

Drive the D921 up from Gèdre and then the D922 through the Héas valley to where the tarmac ends at the auberge du Maillet, leave the vehicle there, and cover the last 275 metres of climb the way everyone now has to — forty minutes on foot, or on the tourist train

Walk the circuit of the cirque floor — four kilometres across at about 2,200 m — and notice what is missing the whole way round: not a single tree or tall bush anywhere inside the ring, because of the climate trapped in it

Stand on the floor and read the rim round: the Pic de la Munia at 3,133 m is the highest, with the Petite Munia at 3,096 m, the Serre Mourène at 3,090 m and the Pic Heid at 3,022 m all over three thousand beside it — then find the muraille de Barroude, the single wall made by the Pic Heid, the Petit pic Blanc and the Pic de Gerbats together

Climb to the lacs des Aires at 2,342 m, the highest of the cirque's lakes, and on the way down find the lac de Serre Longue at 2,190 m and the lac d'Esbarris at 2,139 m — then work out where the Maillet, the Gabiédou, the Cot and the gave des Touyères come together to make the gave de Héas

Find the Hail de Pout, where a dig in 2018 turned up pottery showing that shepherds were living up here in small summer dwellings for some two hundred years between 2300 and 2100 BC, and work out from the ground why they put their huts where they did

Troumouse is one of the largest glacial cirques in the Pyrenees and in Europe, four kilometres across with a floor at about 2,200 m, ringed by summits from the Pic de Bounèu at 2,726 m round by the Pène Blanque, the Mont Arrouy, the Pic de la Munia at 3,133 m and the Petite Munia to the Pic de la Sède. Its climate leaves it without a tree or a large bush anywhere in it. Gavarnie, one valley west, is among the most visited sites in the whole range; Troumouse is reached up a toll road that ends in a car park and a shuttle, and feels like another country.

The Cirque de Troumouse: The Quiet Giant Next to Gavarnie

Walk in to the Circo de Gredos and the Laguna Grande in the floor of it

Work out the vegetation bands as you climb: holm oak, then Pyrenean oak, then broom, then bare grass

Get close to the western ibex, which will not move for you, and work out why the largest population of the subspecies is on this one range

Climb towards the Almanzor at 2,592 metres if the weather and your legs allow

Come back at dusk and listen to the rut in autumn, which carries a long way in a cirque

Gredos runs across Ávila, Cáceres, Madrid and Salamanca, topping out at the Almanzor at 2,592 metres, with the Circo de Gredos — a glacial cirque with a lagoon in the floor of it — in the central sector. The vegetation stacks in clear bands: holm oak to about 550 metres, Pyrenean oak from there to 1,800, broom scrub to 2,300 and bare summit grassland above that. The western ibex, Capra pyrenaica victoriae, has its largest population here across Ávila and Cáceres, and the animals on the high ground are entirely unbothered by walkers.

Gredos: Ibex Above the Tree Line

Get to an observatory above the strait in late August or September and watch the southbound passage

Work out why the birds come here: soaring birds need thermals, thermals do not form over sea, so they cross at the narrowest point

Learn to tell honey buzzard from common buzzard and black kite from red at a distance, which is most of the skill

Come back in spring for the northbound passage, which is a different set of species at different times

Check the wind before you go — Levante or Poniente decides which side of the strait the birds use

Soaring birds cannot cross open water in any quantity — they need rising thermal air, and thermals do not form over the sea. So raptors and storks moving between Europe and Africa are funnelled into the narrowest crossings, and the Strait of Gibraltar is one of the three great bottlenecks on earth alongside Falsterbo and the Bosphorus. Honey buzzards, black kites, short-toed and booted eagles, griffon vultures, black and white storks all pass over this fourteen-kilometre gap, in numbers, twice a year.