Find the frieze on Santiago and work out that the figures below Christ are ordinary trades

Find the bulls on the portal of Santa María del Camino and the legend behind them

Read what Aymeric Picaud wrote about this town in the 12th century and see whether it still fits

Find out who the Infantes de Carrión were and what they do in the Poema de Mio Cid

Walk a stretch of the Camino out of town, which crosses seventeen kilometres of nothing to Calzadilla

Carrión was one of the great towns of the Camino Francés — Aymeric Picaud's 12th-century pilgrim guide describes it as prosperous and full of bread, wine, meat and everything — and it has two Romanesque churches with frieze sculpture of the first rank. Santiago has a frieze of Christ in Majesty with the trades of the town carved beneath it, and Santa María del Camino has bulls carved on its portal from a local legend about a tribute of a hundred maidens. The town also gave Spanish literature the Infantes de Carrión, the villains of the Poema de Mio Cid.

Carrión de los Condes: Romanesque on the Camino

Walk right round the outside and count the corbels under the eaves, which is where the carving is

Work out why it looks so clean: a restoration from 1894 onwards that removed everything added after the 11th century

Find the connections to Jaca cathedral and decide whether the same hands worked on both

Work out its place on the Camino, and what a church of this quality was doing in a small Palencia town

Ask yourself whether stripping a building back to one century is restoration or invention

San Martín de Frómista was built in the second half of the 11th century by order of Doña Mayor of Castile, as part of a monastery that has since vanished; it is first documented in 1066 with work already under way. It sits directly on the Camino de Santiago and it is one of the principal prototypes of European Romanesque — related to the Palencia school and to Jaca cathedral, where some of the same masons probably worked. After it was made a national monument in 1894 the architect Manuel Aníbal Álvarez Amoroso stripped away every later addition to return it to its original state, which is why it is so unusually pure and slightly unreal.

Frómista: The Textbook Romanesque Church

Walk the gantries over the mosaics and find the family portraits in the main one

Work out the two phases: a 1st-century villa, and a complete 4th-century rebuild

Find the bath building and the circular room whose purpose nobody has established

Find out how it was discovered — a farmer flattening a bump in his own field in 1968

Look at the 2009 shelter building itself, which won a competition and is worth a minute on its own

In the summer of 1968 a landowner in Pedrosa de la Vega set about levelling a slight rise in a field and found a Roman villa under it. There are two phases: a 1st-century farm that ran to the end of the 3rd, and a complete rebuild in the 4th at the height of the recovery under Constantine and Theodosius. It was owned by a dynasty of aristocratic landowners, and their portraits are in the main mosaic. Paredes and Pedrosa won the competition to cover the site and their building opened in April 2009 — which is why you can walk over the mosaics rather than peer at them.

La Olmeda: A Roman Villa Found by Accident

Pick a section of at least a week and walk it properly, carrying what you need

Get a credencial stamped at every stop, which is what the Compostela is issued against

Walk the meseta rather than skipping it, because it is the part that does the work

Stay in albergues rather than hotels for at least part of it

Work out why people have kept doing this for a thousand years, which is not a question with one answer

Get to the Praza do Obradoiro and work out what you actually think about having arrived

Everything else in this collection is a day. This is not. The Camino Francés runs about 780 kilometres from Saint-Jean-Pied-de-Port over Roncesvalles, through Pamplona, Puente la Reina, Estella, Logroño, Burgos, the meseta, León, Astorga, O Cebreiro and Galicia to Compostela, and people have been walking it for over a thousand years. The meseta stretch between Burgos and León is the part most people dread and most people end up remembering, because there is nothing to look at and nothing to do but walk. A week gets you a substantial section; the whole thing takes about five.

The Camino de Santiago: The Whole Thing

Look at the tower of San Tirso and work out that every arch in it is brick

Find San Lorenzo and compare the two towers

Work out why brick: there is no good building stone on this stretch of meseta

Find what is left of the monastery Alfonso VI favoured and where he is buried

Work out that this is where Mudéjar brick architecture in Castile and León effectively starts

Sahagún had one of the most powerful monasteries in medieval Spain, favoured by Alfonso VI, who is buried there — and almost nothing of it is left. What survives instead is something better: San Tirso and San Lorenzo, two 12th and 13th-century churches built in brick rather than stone, with blind arcading stacked up their towers. They are the beginning of Mudéjar brick architecture in Castile and León, and they exist because there was no good building stone on this part of the meseta and the masons used what there was.

Sahagún: Brick Where There Was No Stone

Work out that nine of every ten biscuits eaten in Spain once came from this one town

Go to Santa María la Real and the Romanesque study centre inside it

Drive a loop of the 12th-century churches around the town, which are among the densest in Europe

Climb to the castle above the town for the view over the Pisuerga

Find out what happened to the other three biscuit factories

In the 1960s Aguilar de Campoo had five biscuit factories — Gullón, Ruvil, Fontaneda, Tefe and Fontibre — and nine out of every ten biscuits eaten in Spain came out of this one small Palencia town. Two big factories still run. The town is also the centre of one of the densest concentrations of Romanesque architecture in Europe: the monastery of Santa María la Real below the castle now houses a Romanesque study centre, and there are scores of 12th-century churches within a short drive.

Aguilar de Campoo: Nine Out of Ten Biscuits in Spain

Go into Santa María de Valverde and work out that nothing here was built — it was dug out

Find the anthropomorphic graves cut into the sandstone outside, shaped to the body

Find the Romanesque bellcote added to the outside of a church that has no outside walls

Drive the valley and find more of them — Arroyuelos, Cadalso, the hermitages at Villamoñico

Work out why here: the Ebro valley sandstone is soft enough to carve and hard enough to stand

Valderredible in southern Cantabria is where the Ebro valley's soft sandstone allowed people to cut churches directly out of the rock rather than build them — hollowed naves, carved columns, and anthropomorphic graves cut into the stone outside. Santa María de Valverde is the best of them, probably the Santa María la Sotarraña named in the cartularies of Covarrubias and Santa María de Aguilar between the 10th and 13th centuries, with a Romanesque bellcote added on the outside later. Rock hermitages like Los Ventanos at Villamoñico are scattered across the same valley.

Valderredible: Churches Cut Into the Rock

Climb to the keep of the 15th-century castle for the view over both rivers

Walk the walled village and work out that the roofs and the walls are the same slate

Work out why a frontier town was needed here and who it was facing

Drive up to the Lago de Sanabria, which is a short way up the valley

Go on into the Sierra Segundera, which runs into the Portuguese Montesinho

Puebla de Sanabria stands on a hill where the Tera and the Castro meet, with a 15th-century castle of the counts of Benavente on the highest point and a walled village of stone and slate below it — one of the best-preserved in this corner of Zamora, right against the Portuguese border. It was a frontier town for centuries and it looks like one. The Lago de Sanabria is a short drive up the valley, and the Sierra Segundera behind it runs into the Portuguese Montesinho.