Stand in front of the cathedral, begun in 1219, and work out why it is nicknamed the kneeling one

Find the Gothic paintings in the nave under the organs, including the Slaughter of the Innocents

Find out who Álvaro Cunqueiro was and read something of his set in a version of this town

Eat tarta de Mondoñedo, which the town has made for generations

Walk the old quarter and work out what a Galician capital looked like before it stopped being one

Mondoñedo was one of the seven capitals of the Kingdom of Galicia and a bishop's seat, and then the world moved and it did not. What is left is a small town with a cathedral out of all proportion to it, begun in 1219 and well advanced by 1246 — Romanesque with Gothic transept, sacristy and a five-metre rose window of the 14th century in the west front. It is nicknamed the kneeling cathedral for its perfect proportions and low height. Álvaro Cunqueiro, one of the great Galician writers of the 20th century, was born here and set much of his work in a version of this town. The local sweet is the tarta de Mondoñedo.

Mondoñedo: A Capital That Stopped

Check the tide table before you do anything else, and time your visit for low water

Walk under the arches — over thirty metres of eroded slate and schist, which is where the name came from

Go into the caves and sand passages that are only open at the bottom of the tide

Come back at high tide and walk the clifftop path east towards Esteiro to see the same place as an unbroken cliff

Work out why the tide is the whole point here: this stretch of the Rasa Cantábrica is almost flat, so the sea comes back across it quickly

Its real name is the beach of Augas Santas, ten kilometres west of Ribadeo on the Cantabrian coast, but nobody calls it that. At high tide it is a cliff. At low tide the sea pulls back off a long sweep of sand walled by slate and schist eroded into arches over thirty metres high that look exactly like the flying buttresses of a cathedral, with caves and sand corridors running back between the rock. On spring tides you can walk along the sand to the neighbouring beaches — and the coast here is nearly horizontal, so the water comes back fast.

Praia das Catedrais: The Beach That Only Exists at Low Tide

Find the Torre de los Moreno of 1915 and work out what an indiano was

Walk the Eo estuary, which with the Oscos hills behind it is a UNESCO Biosphere Reserve

Cross the Eo bridge and work out that the far side is Asturias

Go up to Santa Cruz above the town for the view over the estuary and the coast

Work out what emigration to Latin America did to towns along this coast, and what it built when it came back

Ribadeo sits at the mouth of the Eo, which is the border with Asturias, and the Eo estuary with the Oscos hills behind it is a UNESCO Biosphere Reserve. The town made money from emigration to Latin America and came back in the form of indianos — returning emigrants who built showy houses, of which the Torre de los Moreno of 1915 is the extravagant example. The Eo bridge is a kilometre and a half of motorway over the estuary. Praia das Catedrais is ten kilometres west.

Ribadeo and the Mariña Lucense

Watch a navaya being forged and find out why the handle is made the way it is

Find the water-driven mills, forge hammers and fulling machines still working on the streams

Work out how far back this goes: six forge hammers recorded in the Ensenada cadastre in the 18th century

Walk between the hamlets on the old paths — this is one of the greenest, wettest corners of Spain

Buy a knife made here rather than a souvenir version of one

Taramundi in the far west of Asturias had a working iron industry in the 18th century — the Ensenada cadastre records six forge hammers and a set of smithies — and it never entirely stopped. The knives and folding navayas made here are still forged by hand, and the whole trade runs on water — the mills, forge hammers and fulling machines that shape the blades are driven by the streams, as they always have been. It is one of the wettest corners of Spain, which is the reason the industry could exist here at all.

Taramundi: Knives, Water and Iron

Watch one of the Holy Week processions of Viveiro's eight brotherhoods

Walk through the Puerta de Carlos V and find the three coats of arms

Find the monument to the Magdalena and the Palomo on the rocks by Covas beach

Drive up to the Mirador de San Roque for the view over the ría

Viveiro's Holy Week is one of the oldest religious celebrations in Galicia, held without a break since the 13th century, with eight brotherhoods carrying the processions of the Passion; it is a festival of international tourist interest. The town enters through the Puerta de Carlos V, a Plateresque gate finished in 1554 with the emperor's arms between those of Galicia and Viveiro. On the rocks by Covas beach a monument remembers the frigate Santa María Magdalena and the brig Palomo, wrecked together in a storm in 1810 with more than 500 dead.

Viveiro: A Holy Week Kept Since the 13th Century

Walk out past the lighthouse to the northernmost point of the Iberian peninsula

Sit at the headland with binoculars and count the gannets and shearwaters passing

Find the ruins of the American LORAN station

Look back along the coast towards Cabo Ortegal

Estaca de Bares, in Mañón, is the northernmost point of Spain and of the Iberian peninsula, and its lighthouse is the most northerly on the peninsula. It is also an outstanding place to watch seabirds on migration: more than 280,000 have been counted passing in a year, gannets above all, with Manx and Cory's shearwaters. From the early 1960s the US Coast Guard ran a LORAN navigation station here, taken over by the US Air Force in 1978; its buildings are ruins now.

Estaca de Bares: The Northernmost Point of Spain

Go to the Festival do Mundo Celta and hear the pipe bands from the Celtic nations

Find out how a town pipe band started a free festival in 1978

Walk Morouzos beach and the pine wood where the festival camps

Walk along the ría de Ortigueira, Galicia's largest Ramsar wetland

Find the castro of Punta dos Prados and its ritual steam bath

The Festival Internacional do Mundo Celta was started in 1978 by the Santa Marta de Ortigueira pipe band, and it has been free since 1985: a festival of the folk music of the Celtic nations, usually on the second weekend of July, declared of international tourist interest in 2005. People camp on Morouzos beach and in the pine wood behind it. The rest of the year Ortigueira is a quiet town at the head of its ría, the largest of Galicia's five Ramsar wetlands, with the 19th-century Teatro de la Beneficencia in a wing of the building that also holds the town hall and the Iron Age castro of Punta dos Prados, which had a ritual steam bath, on the far shore.

Ortigueira: The Festival of the Celtic World

Walk the boardwalks out to the mobile dune and work out how far it moves in a year

Find the two lagoons and work out that one is salt and one is fresh, and what that does to the birds

Work out why a dune this size is unusual on this coast

Go out to the Corrubedo lighthouse and read what this stretch of coast has done to shipping

Stay off the dune itself and work out from the signs why walking on it is the one thing that destroys it

The dune at Corrubedo is about a kilometre long, up to twenty metres high, and moving — a mobile dune of a size unusual on the Atlantic coast of Iberia, sitting between the sea and two lagoons, Carregal and Vixán, one salt and one fresh. The whole complex is a natural park and a Ramsar site, and the two different lagoons side by side is why the bird list is as long as it is. Behind it the coast runs out to the Corrubedo lighthouse on one of the most dangerous stretches of the Costa da Morte.

Corrubedo: The Biggest Moving Dune in Galicia

Look at the cathedral from a distance and work out that the towers of 1408 and 1424 are not decoration

Find the west portal, finished by 1225 and reckoned the first Gothic sculptural ensemble in the Iberian peninsula

Walk the international bridge across the Miño to Valença and back, which is what the Portuguese Way does

Work out why a cathedral needed arrow slits, and who was on the other side of the river

Follow the Portuguese Way out of the town, which is the busiest Camino route after the Francés

Tui faces Valença across the Miño, which is to say it faces Portugal, and for centuries that meant being fortified — which is why its cathedral has crenellations, towers and arrow slits and reads from a distance as a castle. It was one of the seven capitals of the old Kingdom of Galicia. The west portal, finished by 1225 when Bishop Esteban Egea consecrated the building, is considered the first Gothic sculptural ensemble in the Iberian peninsula, and the defensive look was reinforced later with the tower of Soutomaior in 1408 and San Andrés in 1424. The Portuguese Way crosses the international bridge here into Valença.