Climb the Mudéjar towers of Teruel, the Torre de El Salvador and the Torre de San Martín, built in the 12th and 13th centuries and part of the 'Mudéjar Architecture of Aragón' UNESCO World Heritage Site

Visit the Cathedral of Teruel, with its Mudéjar tower and ceiling

See the mausoleum of the Lovers of Teruel, Diego de Marcilla and Isabel de Segura, whose tale is dated to 1217

Taste jamón de Teruel, the region's cured ham

Mudéjar is what happened when Muslim craftsmen kept working in Christian Spain after the reconquest — brick, glazed ceramic and geometric patterning applied to churches and towers, an Islamic building tradition serving a Christian one. Teruel has the best of it, and the towers of El Salvador and San Martín are on the UNESCO list. The town's other possession is the Lovers of Teruel: Diego and Isabel, dated to 1217, who by the story died of grief within a day of each other and lie in an alabaster tomb with their hands not quite touching.

Teruel: Mudéjar Towers and the Lovers

Walk the wall up the ridge above the town and look back down into it

Work out the political anomaly: an Islamic taifa handed to a Christian family by agreement, then held independent of Castile and Aragon from 1170, with its own bishop

Find the rodeno — the reddish local stone that gives every building in the town the same colour

Go into the Cathedral of El Salvador in the middle of the old town

Look at the forged ironwork on the houses, which is the local vernacular and is everywhere once you notice it

Albarracín is named after the Banu Razin, a Berber clan who made themselves the sovereign dynasty of their own taifa here in the 11th century. What happened next is the unusual part: the taifa passed to the Azagra, a Christian family of Navarrese lineage, by cession rather than conquest, and from 1170 they held it independent of both Castile and Aragon — to the point of running their own bishopric. The town is built of rodeno, the local reddish stone, and is walled, vertical and almost entirely intact.

Albarracín: The Taifa That Stayed Independent

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.

Cantavieja and Mirambel: The Hospitallers' Maestrazgo

Walk round the upper lagoons — the Gitana, the Tejo and the little Tejo — and name the colour of each

Look down into the lagoons from the rim and work out how a collapsed sinkhole fills with groundwater

Walk among the Torcas de los Palancares, the dry sinkholes of the same geology

The lagoons of Cañada del Hoyo are seven karst lakes — five lagoons and two smaller lagunillos — in the Palancares hills 40 kilometres from Cuenca, fed from underground and by rain, and a Natural Monument since 2007. Each looks a different colour because of microorganisms, submerged plants, the light and the season, though a glass of water from any of them is clear: the Tejo is dark blue, the little Tejo black, Cardenillas sky blue, the Parra blue. The Gitana was blue too, and has been green since the 1980s from the number of people bathing in it. Their levels drop a little every year as the aquifer is pumped. Eight kilometres away the Torcas de los Palancares are the same sinkholes without the water.

Cañada del Hoyo: Seven Lagoons, Seven Colours

Walk the circuit and work out that every shape in it was cut by water out of a seabed

Work out the sequence: Tethys seafloor 90 million years ago, lifted by the alpine orogeny, then karst weathering ever since

Find the fossils in the rock, which are the direct evidence of what this was

Work out why it was protected as early as 11 June 1929, which is very early for a Spanish natural site

Go on into the wider Serranía de Cuenca and find the Ventano del Diablo over the Júcar gorge

Ninety million years ago this was the floor of the Tethys sea. The alpine orogeny at the end of the Cretaceous lifted it out of the water, and karst weathering since has cut the limestone into freestanding blocks, mushrooms, corridors and arches at 1,500 metres among pine forest near Valdecabras. It was declared a Natural Site of National Interest on 11 June 1929 and now sits inside the Serranía de Cuenca natural park. The land is private and there is a modest entry charge, which is worth knowing before you drive out.

The Ciudad Encantada: A Cretaceous Seabed, Weathered

Walk the castle enclosure and work out how much ground it actually covers

Work out the political story: Aragonese in 1128, Castilian, Almoravid, then an independent lordship from about 1139

Drive into the Alto Tajo and find the river canyons, which are among the deepest in inland Spain

Find out what the proposed Molina-Alto Tajo geopark covers — seventy municipalities and over four thousand square kilometres

Find the Romanesque bridge and the Torre de Aragón above the town

Alfonso I of Aragon took Molina in 1128; his brother Ramiro II handed the lands to Castile; the Almoravids took them back; and around 1139 Manrique de Lara took them again and made the place an independent lordship with himself as its first lord. The Señorío de Molina kept a separate identity for centuries and the town still uses the name. Its castle is one of the largest in Spain by enclosed area. It sits beside the Alto Tajo natural park, one of the greatest concentrations of river canyons in inland Iberia, and inside a proposed geopark covering seventy municipalities and 4,186 square kilometres.

Molina de Aragón: A Lordship of Its Own

Walk La Mina and work out that a town of this size drove a tunnel through a mountain between 1555 and 1560

Work out what the problem was that made it necessary

Go into the basilica of Santa María de los Sagrados Corporales and find the apse, the first surviving Romanesque-to-Mudéjar transition

Walk the walls up over San Jorge and San Cristóbal, which is a considerable climb

Find out what the Sagrados Corporales relic is and why this basilica was built round it

Daroca is strung along a valley between two hills, San Jorge at 855 metres and San Cristóbal at 931, with walls running up over both. The problem with a town in a valley is that the valley floods, so between 1555 and 1560 the townspeople drove a tunnel — La Mina — straight through the hill to carry floodwater out the other side. It is reckoned one of the most important public works of the 16th century anywhere in Europe. The basilica holds the Sagrados Corporales relic, and its apse is the first surviving example of the transition from Romanesque to Aragonese Mudéjar.

Daroca: A Tunnel Through a Mountain, in 1560

Take a boat to the Columbretes Islands, 49km off the coast near Oropesa del Mar, a volcanic archipelago whose name comes from the Latin coluber for its snakes

Dive in the Columbretes marine reserve, protected since 1990 and covering 400 square kilometres

Climb to the lighthouse on Illa Grossa, the largest island at 67m, standing in an ancient volcanic crater

Look for Audouin's gulls, of which the islands hold one of the world's most important colonies

The Columbretes are volcanic cones sticking out of the Mediterranean 49 kilometres off Castellón, uninhabited except for the lighthouse keepers who used to live there, and named from the Latin coluber for the snakes that infested them — the 19th-century lighthouse builders burned the vegetation off to clear them. Left alone since, the islands and the water round them became a marine reserve in 1990 covering 400 square kilometres, and the diving is the best on the Spanish Mediterranean coast because nothing has been fished out of it for a generation.

The Columbretes: Volcanic Islands Off Castellón

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.