Tour Peñíscola Castle, built by the Knights Templar between 1294 and 1307, where the antipope Benedict XIII, Papa Luna, lived from 1415 to 1423 and where El Cid was filmed after its 1960 restoration

Walk the Serra d'Irta Natural Park behind the coast south of Peñíscola

Walk the old town on its rock, joined to the mainland by a narrow strip of sand

Peñíscola is a fortified town on a rock joined to the mainland by a sand bar, with a castle the Knights Templar built between 1294 and 1307 on top of it. Its strangest period came when Benedict XIII — Papa Luna, the Avignon antipope deposed by the Council of Constance — refused to accept that he was not pope, retreated here in 1415 and held out until he died in 1423, excommunicating everyone who disagreed with him. The castle was restored in 1960 and immediately used as a location for El Cid.

Peñíscola: The Templar Castle Where the Antipope Held Out

Eat llagostí de Vinaròs in Vinaròs, and find out why it costs what it does

Go to the fish auction in the port in the afternoon and watch the boxes go

Eat the Benicarló artichoke, which has a protected designation and a following

Work out why this corner stayed a fishing coast when everything south of it did not

The northern tip of the Valencian coast, where Castellón province runs into the Ebro delta, is a working fishing coast rather than a resort one. Vinaròs lands the llagostí — a prawn with its own reputation and its own price, auctioned in the port most afternoons — and Benicarló grows an artichoke with a protected designation that people drive a long way for. Behind them the Serra d'Irta runs down to the sea as one of the very few undeveloped stretches left on the Mediterranean coast of Spain, protected as a natural park.

Vinaròs and Benicarló: Llagostí, Artichokes and a Working Fishing Coast

Go up to the shelters with the guide and find the archers and the hunting scenes

Work out what makes Levantine art different: it shows narrative, with people acting, not just animals

Work out why the paintings are under overhangs and what that has to do with their survival

Find out what the 1998 UNESCO listing covers and how many sites are in it

Look out from the shelters at the Ports behind and the delta to the north, and work out why people were here

The shelters at the Ermites de la Pietat above Ulldecona hold one of the densest concentrations of Levantine rock art anywhere — hunting scenes, archers, deer and human figures painted on the rock overhangs, part of the Rock Art of the Mediterranean Basin on the Iberian Peninsula listed by UNESCO in 1998. Levantine art is unusual because it shows narrative: people doing things to each other and to animals, rather than isolated beasts. Below the shelters the Montsià and the Ports run away inland and the Ebro delta lies to the north.

Ulldecona: Rock Art on the Ports Edge

Watch waterbirds in the Ebro Delta Natural Park, established in 1983, home to the world's largest colony of Audouin's gulls and 95 breeding bird species

Visit the MónNatura Delta de l'Ebre centre in Deltebre

Take a boat trip on the Ebro from Deltebre down to the river mouth

Cycle the tracks through the rice fields, flooded in spring and again in winter when they fill with birds

The Ebro delta is 320 square kilometres of flat land the river has built out into the Mediterranean, and it is one of the largest wetlands in the western Mediterranean — rice fields, lagoons, salt pans and dune spits, with 95 breeding bird species and the largest colony of Audouin's gull in the world. It is also shrinking: dams upstream hold back the sediment that used to replace what the sea takes, so the delta is now losing ground and sinking, which makes it one of the most exposed places in Spain to sea level rise.

The Ebro Delta: Audouin's Gulls, Rice Fields and the River Mouth

Climb Mont Caro, at 1,441m the highest point of the province of Tarragona

Look for the Spanish ibex, which lives in the Ports massif

From the top, pick out the Ebro delta and the Mediterranean below

The Ports de Tortosa-Beseit is a limestone massif where Catalonia, Aragon and Valencia meet, rising to Mont Caro at 1,441 metres with the Ebro delta and the Mediterranean laid out below it. It holds one of the strongest populations of Spanish ibex in the country.

Mont Caro: The Top of the Ports and the Ibex

Go into the cathedral of Santa Maria and its cloister, built in the 12th and 13th centuries

Stand in the patio of the college of Sant Jaume and Sant Maties, the only Renaissance patio in Catalonia

Find out who the college was built for in 1564, and what happened after 1610

Walk in the Jardins del Príncep, the town park

Tortosa sits on the Ebro at the head of its delta. Its cathedral stands on the site of a Romanesque one begun in 1158; the first stone of the Gothic cathedral was laid in May 1347, and the Baroque façade begun in the 1620s was left unfinished in 1757. Round the corner the Reials Col·legis are the most important Renaissance buildings in Catalonia: the college of Sant Jaume and Sant Maties was begun in 1564 to educate young converted Muslims, and after the Moriscos were expelled in 1610 it took in the poor boys of the city instead. Its courtyard is the first, and only, Renaissance patio in Catalonia.

Tortosa: The Only Renaissance Patio in Catalonia

Walk the circuit of the medieval wall and work out that the town has no outside

Climb to the castle on the crown of the rock for the view over Els Ports

Work out the building sequence: Muslim walls of 1084, rebuilt from 1324 by Aparisi Joan, most of it finished between 1358 and 1465

Find the aqueduct outside the walls and follow where the town's water came from

Eat what this altitude produces — truffle in winter, lamb, and the local cheeses

Morella stands on an isolated hill in Els Ports, in the far north of Castellón province, wrapped in a complete medieval wall with a castle on the crown of the rock. The walls were begun by a master of walls named Aparisi Joan between 1324 and 1330, with most of the work done under Peter IV of Aragon and after, between 1358 and 1465 — and all of it built on the base of the Muslim walls of 1084. It is high, cold and remote, and the whole town is inside the circuit.

Morella: A Walled Town on a Thousand-Metre Hill

Visit the ruins of Scala Dei Charterhouse, founded in 1194, whose Carthusian monks introduced viticulture to the region and gave Priorat its name from the prior's authority over seven villages

Taste a Priorat DOQ wine in Gratallops, where René Barbier and Álvaro Palacios led the region's revival in the 1980s

Walk the terraced vineyards on llicorella, the black and red slate soil laced with mica that forces the Garnacha and Cariñena vines deep

Carthusian monks founded Scala Dei in 1194 and planted vines, and the priory's authority over seven villages gave the region its name — Priorat. The soil is llicorella, black and red slate shot through with mica, which holds almost no water and forces old Garnacha and Cariñena vines to send roots metres down to find it. The result is concentrated and expensive. The region had all but died by the 1970s; René Barbier, Álvaro Palacios and a handful of others revived it in the 1980s, and it is now one of only two DOQ regions in Spain.

Priorat: Scala Dei and the Llicorella Vineyards

Walk Cantavieja's arcaded Plaza de Cabrera, in the capital of the Maestrazgo founded in 1197 and a Cultural Heritage Site since 1981

Walk the medieval streets of Mirambel, a village of about 110 people at 993m elevation counted among the most beautiful in Spain

Find the Hospital de San Roque of 1775 and the parish church of the Asunción, enlarged in 1745, from Cantavieja's wool-trade century

The Maestrazgo is the high, empty, broken country of southern Teruel — limestone, deep canyons, and villages at a thousand metres that have been losing people for a century. Cantavieja was founded in 1197 and ran the region for the Knights of the Order of St John; Mirambel has about a hundred and ten people and an intact walled centre. It is one of the most thinly populated areas in western Europe, part of what Spaniards call la España vaciada, the emptied Spain, and that emptiness is precisely what makes it worth driving into.