Go into the church and find the grille made by the Carthusian monk Francisco de Salamanca

Find the walnut choir stalls carved in the 16th century, removed to Madrid in 1883 and returned here in 2003

Work out the founding story: a king who burned a charterhouse in France and built this one in 1390 to make up for it

Walk the Lozoya valley around it, which is inside the Sierra de Guadarrama National Park

Cross to the Puente del Perdón and find out what it was called that for

Henry II of Castile ordered a charterhouse built in the Lozoya valley in 1390 — the first Carthusian foundation in Castile — and tradition says he chose that order because his own army had burned one of their houses during the war in France. He picked the spot himself, beside a hermitage already there, and told his son, the future John I, exactly where. It was Carthusian until 1835. The grille separating the congregation from the monks was made by a Carthusian monk, Francisco de Salamanca, and the 16th-century walnut choir stalls were taken to Madrid in 1883 and only brought back in 2003.

El Paular: The First Carthusian House in Castile

Hike from the Puerto de Cotos to the summit of Peñalara at 2,428m, the highest peak of the Sierra de Guadarrama

Look down on the glacial lake and cirques beneath Peñalara, protected as the Peñalara Natural Park in 1990 and now part of the Sierra de Guadarrama National Park, declared on 26 June 2013

Visit the Peñalara visitor centre at the Puerto de Cotos, the start of the summit path

Peñalara is the highest point of the Sierra de Guadarrama at 2,428 metres, an hour from Madrid, and the corries beneath it hold the southernmost glacial lakes in Europe of their kind — cut by ice that has been gone for ten thousand years. It was protected as a natural park in 1990 and folded into the Sierra de Guadarrama National Park when that was declared on 26 June 2013. The path from Cotos is short and popular, which is why numbers to the summit are now limited at busy times.

Peñalara and the Glacial Cirques

Be there when the fountains run and work out that all twenty-one are driven by slope alone, with some jets clearing forty metres

Find El Mar, the 216,000 cubic metre reservoir at the top of the garden that feeds the whole system

Work out the contradiction: a Spanish king raised at Versailles who said he wanted another Escorial and built this instead

Find out why the palace is irregular — the 1719 order that nothing already standing was to come down — and why the fountain statues are lead rather than bronze

Go to the Real Fábrica de Cristales in the village, the royal glass works that supplied the palace

Philip V was born at Versailles in 1683 and raised at the court of his grandfather Louis XIV, and when he came to build himself a retreat below the Guadarrama it showed. He ordered a chapel here in 1719 with the instruction that nothing old was to be demolished, which is why the result is irregular and reads as a set of additions. The main works began in 1721. The gardens were laid out by the French gardener René Carlier, who used the natural slope of the surrounding hills both for the perspective and as the power source for all twenty-one monumental fountains; Carlier died in 1722 and Étienne Boutelou continued the work. Where Versailles struggled for water pressure, La Granja simply fell downhill — and some of its jets clear forty metres.

La Granja de San Ildefonso: Versailles on the Meseta

Walk the upper gallery and work out that this is a palace wearing a castle's clothes

Find the Romanesque-Mudéjar church swallowed inside the structure when the castle was built over it

Work out Juan Guas's Isabelline Gothic and its Hispano-Muslim borrowings, and what he did next at Guadalajara

Find the remains of the old castle nearby, which this one replaced

Walk up into La Pedriza behind it, the granite massif the family's land ran into

The Mendoza were one of the most powerful families in late medieval Castile, and in the last third of the 15th century they replaced their old fortress at Manzanares with something grander — a palace-fortress built over a Romanesque-Mudéjar church, which was simply absorbed into the structure. Juan Guas drew it in Isabelline Gothic with Hispano-Muslim influence, and it is regarded as the precursor of his Palacio del Infantado at Guadalajara, where he settled the template for a Catholic Monarchs palace. It stands under the Guadarrama beside the Santillana reservoir, with La Pedriza behind it.

Manzanares el Real: A Castle Built to Be Lived In

Walk beside the Roman Aqueduct, built of about 25,000 granite blocks fitted without mortar, spanning 818m with over 170 arches and reaching 29m

Tour the Alcázar, a fortress documented for the first time in 1122 that became a favoured royal residence

Enter the Cathedral, built between 1525 and 1577 and one of the last Gothic cathedrals in Europe

Eat cochinillo asado, roast suckling pig, at a mesón beside the aqueduct such as Mesón de Cándido

The aqueduct at Segovia is about 25,000 granite blocks held together by nothing at all — no mortar, no clamps, just the weight and the cut of the stone — carrying water 818 metres across the town on over 170 arches, up to 29 metres high. It was built in the 1st or 2nd century AD and it carried water until the 1970s. Above it the Alcázar sits on a rock where two rivers meet, first documented in 1122, and the cathedral of 1525–1577 is one of the last Gothic cathedrals built anywhere in Europe.

Segovia: The Aqueduct, the Alcázar and a Late Gothic Cathedral

Walk the paved sections up towards the Fuenfría pass through the pine forest

Find the bridges — Enmedio, Descalzo, La Venta and Reajo — proposed for protection in 1981

Work out the argument: the visible track is not the 1st-century road along its whole length

Find out what the Cercedilla milestone of 1910 settled and what it did not

Cross the pass and look down into the Valsaín valley on the Segovia side

A Roman road crossed the Guadarrama here, linking Segovia with Miaccum and on to Toledo, over the Fuenfría pass between the Fuenfría and Valsaín valleys. A milestone turned up at Cercedilla in 1910 and let the archaeologist Antonio Blázquez date the crossing securely, though his reconstruction of the line has been argued over ever since — later work by Rivas López, Rodríguez Morales and Moreno Gallo showed the present paved track does not follow the 1st-century road everywhere. The road and its four bridges were put forward for protection on 2 July 1981.

The Fuenfría: A Roman Road Over the Guadarrama

Walk the wall — 11th-century Moorish work restored in the 15th, and one of very few surviving circuits in the Madrid region

Work out how the defence works: the wall on one side, the Lozoya wrapped round the other three

Go into the Picasso museum and work out how a small town on the Lozoya came to hold a collection like it

Find out who Eugenio Arias was — a barber from Buitrago, and a friend of Picasso

Go into the 15th-century Gothic-Mudéjar castle and the church of Santa María del Castillo of 1321 beside it

Buitrago is one of very few towns in the Madrid region to have kept its walls — Moorish, 11th century, restored in the 15th — on a peninsula with the Lozoya running round it. Inside is a Gothic-Mudéjar castle of the 15th century, the church of Santa María del Castillo of 1321 in the same style, and, unexpectedly, a Picasso museum. Eugenio Arias was a barber from this town and a friend of the artist, and the collection he built is now held here.

Buitrago del Lozoya: Walls and a Picasso Collection

Walk the upper village and work out that the walls and the roofs are the same material — black slate, all of it

Find out about the Reyes de Patones, hereditary kings of a village of seven households, who lasted until about 1750

Work out when and how the kingdom ended: a request for a mayor, and independence from Uceda in 1769

Walk the hillside above, low rocky scrub of rockrose and broom with pine on the north face

Go down to Patones de Abajo, where everyone actually lives now, and see the difference

Patones de Arriba had seven households in 1555 and, by long tradition, its own hereditary kings — the Reyes de Patones — who lasted until about 1750, when the villagers asked to have a mayor instead. In 1769 Patones was granted the status of a village independent of Uceda, which is probably when the last king disappeared. It is the best example of arquitectura negra in the Madrid region: everything, walls and roofs both, built of black slate, on a rocky scrub hillside an hour from the capital.

Patones de Arriba: The Village With Its Own Kings

Stand in the Plaza Mayor and work out why it is irregular — it grew round penned livestock rather than being designed

Look at the tiered wooden galleries and work out that they were built as balconies to watch animals from

Come when the square is sanded for a bullfight or a festival and see what it was always for

Find out that this square played the Spanish bullring in Around the World in Eighty Days, with much of the town as the crowd and Cantinflas as the matador

Climb to the castle ruins and the old church above the town for the view over the Tagus valley

Chinchón's Plaza Mayor is irregular rather than laid out, because it grew: livestock were penned around the houses so their owners could watch them from the balcony without going outside, and that is why the whole square is ringed with tiers of open wooden galleries on stone columns. It is protected as a Historic Ensemble. Several times a year the ground is sanded and the square becomes a bullring, which is what those balconies have always been used for, and the rest of the time it is where the town eats.