Go to the costume museum in Ansó church and work out how many pieces the traditional dress has

Come on the last Sunday in August, when the village wears it

Find out what cheso is and how a dialect survives in one valley and not the next

Look at the chimneys on the houses and work out what they were built that size for

Drive up into the Selva de Oza and walk to the Boca del Infierno gorge

Ansó and Hecho are the two westernmost valleys of the Aragonese Pyrenees, and they kept a distinct identity long after the rest — their own dialect, Aragonese in a form called cheso in Hecho, and a traditional women's costume of such complexity that it is one of the most elaborate surviving folk dresses in Europe, still brought out for the last Sunday in August. The villages are stone and slate with enormous chimneys. Behind them the Selva de Oza and the Valles Occidentales park run up to the French border.

Ansó and the Western Valleys

Taste Roncal, the first cheese in Spain to get a denominación de origen, in 1981

Go to Gayarre's house museum and his mausoleum by Benlliure, and find out who he was

Be at boundary marker 262 on the Ernaz pass on 13 July for the Tribute of the Three Cows

Work out what is being enacted: an arbitral sentence of 16 October 1375, on a ceremony older than the sentence

Drive up into the Belagua valley and the Larra massif above, which is high karst

Roncal was the first cheese in Spain to be granted a denominación de origen, in 1981, and the point of it was to stop other cheeses calling themselves roncal. It is made by hand from raw Latxa sheep's milk in the Navarrese Pyrenees under the Mesa de los Tres Reyes. In 882 Sancho García granted the valley the right to bring its flocks down to winter in the Bardenas Reales, which they had earned fighting the Saracens. The valley also produced Julián Gayarre, the greatest Spanish tenor of the 19th century, whose mausoleum by Mariano Benlliure is in the village of Roncal. And every 13 July, at boundary marker 262 on the Ernaz pass — standing in for the lost Stone of San Martín — the men of the French Barétous valley hand three cows to the men of Roncal, under an arbitral sentence of 16 October 1375 that is considered the oldest treaty in Europe still in force. The ceremony itself is older than the sentence. Navarre made it intangible cultural heritage on 24 January 2011.

The Roncal Valley: Cheese, a Tenor and a Cattle Tribute

Drive the full 40 km of the Aspe valley from Escot up to the col, and ignore the signs for the 8.6 km tunnel that has taken the traffic off this road since it opened on 7 February 2003 — the old pass road is the quiet one now

Stand on the frontier at the col by the Ermita del Pilar, the one building up here, and work out what the pilgrims coming up the Via Tolosane from Oloron-Sainte-Marie were facing: 840 km still to Santiago, down into Aragon on the Camino aragonés

Walk a stretch of the waymarked pilgrims' way down from the col towards Urdos, and find the abandoned works of the Pau to Canfranc railway in the valley beside it — opened in 1928 and shut after a goods train brought down the Estanguet bridge on 27 March 1970

Walk Borce for its medieval houses and the ecomuseum room on the pilgrim road, then cross to Etsaut and look up at the Fort du Portalet clamped to the gorge wall — known as the fort d'Urdos although almost all of it stands in Etsaut

Walk the Chemin de la Mâture above Etsaut, the ledge cut straight into the rock in 1772 so that trees from the bois du Pacq could be brought down to be made into ships' masts, and work out how a mast was got along it

The Somport sits at about 1,632m on the Spanish border where the Aspe valley opens into Aragon, and the Roman road up to it, the Via Tolosane, was the most popular of all the crossings for pilgrims heading to Compostela until the 12th century, when Roncesvalles became the safer choice. The Vandals, Alans, Suebi and Visigoths all came the other way through it in the early fifth century. The Aspe below is still wild country, and for a long time it was the refuge of the Pyrenean brown bear.

The Col du Somport: The Pilgrims' Pass Above the Aspe Valley

Book the guided tour into the salle de la Verna at Sainte-Engrâce, the huge chamber of the gouffre de la Pierre-Saint-Martin opened to the public in 2010, and pace out how far its floor runs before the walls come back into the light

In the church at Sainte-Engrâce bourg, founded in 1085, account for all twelve carved capitals across its three naves, then put a coin in to light the choir and set the Basque chant playing while you look at them

In the cemetery beside the church, find the discoid stelae — the round-headed Basque gravestones — and pick out the oldest carving you can still read

From the auberge Logibar on the D26 below Larrau, walk the rough 45-minute path up to the passerelle d'Holtzarte and cross its 70 m span, more than 130 m above the floor of the Olhadubi gorge

Follow the D113 the five kilometres from La Caserne up to Sainte-Engrâce Bourg and on to where the road runs out against the cirque de Sainte-Engrâce closing the head of the valley

In the Soule, the gorges of Kakuetta were first explored in 1906 by Édouard-Alfred Martel; a kilometre and a half of a gorge just under four kilometres long, 30 to 350 m deep and narrowed at the Grand Étroit to a few metres between its walls, was made walkable, but the site has been closed since a fatal rockfall in 2020 and is being rebuilt as a high-level route. The rest of the valley is open: the church at Sainte-Engrâce was founded in 1085 by the abbey of Leyre in Navarre with a hospital for pilgrims on the road to Compostela, the salle de la Verna has been open to visitors since 2010, and over the hill the passerelle d'Holtzarte, built in 1920 by Italian sawmill workers, carries the GR10 across the Olhadubi gorge 70 m wide and more than 130 m above its floor.

Sainte-Engrâce: The Church of 1085, the Verna Chamber and the Holzarte Footbridge

Walk the full 240m length of the station building and count some of its 365 windows

Find the section preserved as a small museum, documenting the station's role smuggling Nazi gold and hiding refugees between 1942–1944

Look for the plaque honouring Albert Le Lay, the French border guard called "the Schindler of Canfranc" for helping refugees escape

Walk a stretch of the disused rail line heading toward the sealed French border tunnel — the international route has been closed since 1970

Canfranc International station is 241 metres long with seventy-five doors on each side, built to the design of the engineer Fernando Ramírez de Dampierre and modelled on 19th-century French palace architecture. It took five years and was inaugurated on 18 July 1928. International services stopped between 1945 and 1949 over a falling-out with the French government, and then ended altogether on 27 March 1970 when a French freight train derailed and brought down the L'Estanguet bridge on the far side of the border. A new passenger station opened on 15 April 2021 in two rehabilitated freight sheds, and in 2023 a luxury hotel opened inside the old building itself.

Canfranc: The Belle Époque Station on the Border

Walk into the beech and fir and work out the scale: 17,179 hectares, second only to the Black Forest

Come in the last week of October or the first of November, when the beech turns and the whole forest changes colour

Find the ruins of the Orbaizeta arms factory in the middle of the wood

Look for the associated species under the canopy — yew, holly, birch, lime, maple, rowan

Work out what UNESCO added it to in 2017, and what a primeval beech forest actually means

Irati is 17,179 hectares of beech and silver fir in the Navarrese Pyrenees — the largest forest in Navarre and the second-largest beech-fir wood in Europe, beaten only by the Black Forest. Birch, yew, holly, maple, lime, bramble and rowan fill in under the canopy wherever there is enough humidity, which there generally is. In 2017 it was added to the UNESCO list as part of the Primeval Beech Forests of the Carpathians and Other Regions of Europe. Carlos III planned an arms depot at the Orbaizeta forge in the late 18th century, and the ruins of it are still in the wood.

The Irati Forest: The Second-Largest Beech-Fir Wood in Europe

Walk the star-shaped ramparts of the Citadel of Jaca (Castle of San Pedro) — designed for Philip II in 1592 and never involved in a battle

Find the moat and drawbridge of the pentagonal fort, still the only way in

Inside Jaca Cathedral, find the carved capitals of the 11th-century Romanesque nave

Walk the arcaded main street connecting the cathedral to the citadel

Two buildings five minutes apart. The cathedral of San Pedro was begun in the last quarter of the 11th century on the initiative of Sancho Ramírez, at almost the same moment as Santiago de Compostela, and it carries the architectural vocabulary that then travelled the whole Camino — the chequerboard billet moulding and the ball ornament on the interior supports. The citadel is a five-pointed star fort on the Italian model, built outside the town walls and preserved essentially intact: ditch, bastions, scarps and counterscarps, barracks, powder stores and tunnels, entered across a three-arched bridge and a drawbridge. The Spanish army held it into modern times.

Jaca: Citadel and Cathedral

Get to the Plaça Major on a market morning, which is what the square was built for

Buy llonganissa de Vic and work out why the fog and cold of this plain are what cures it

Find the crypt and bell tower of Bishop Oliba's cathedral of 1038 inside the later building

Go into the Museu Episcopal for one of the best collections of Catalan Romanesque and Gothic art anywhere

Come for the Mercat del Ram, the old livestock fair, which is the town's original market

Bishop Oliba consecrated the Romanesque cathedral at Vic in 1038, and its crypt and bell tower are still there inside the later building. The town has always been a place of fairs and markets — the oldest is the Mercat del Ram, a livestock fair — and the Plaça Major is one of the largest arcaded squares in Catalonia, still filling with stalls twice a week. Vic is also the sausage capital of Catalonia: the llonganissa cured here has a protected designation, and the reason is the town's particular combination of cold, fog and altitude.

Vic: A Market Square and a Bishop's Museum

Walk up to the Renclusa and look at what is left of the Aneto glacier from below

Find out how much ice the Maladeta massif has lost in the last hundred years

Climb Aneto with a guide if you are equipped for it — 3,404 metres and the highest in the Pyrenees

Walk the Estós or Vallibierna valleys if you are not, which get you into the same country on foot

Work out why this one valley has more three-thousand-metre peaks around it than any other in the range

The Benasque valley holds the highest ground in the Pyrenees: Aneto at 3,404 metres, the highest peak in the range, with Posets and Maladeta behind it, and the Aneto glacier — what is left of it — on the north face. The Maladeta massif has lost most of its ice in a century, and what remains is one of the clearest things in Spain to point at when talking about what is happening to mountain glaciers. Benasque itself is the base for all of it, and the Posets-Maladeta natural park has more three-thousand-metre peaks than anywhere else in the Pyrenees.