Hear silbo demonstrated across a barranco and work out that this is Spanish, not a code

Try to whistle a word yourself and find out how hard it actually is

Work out why the island needed it: ravines that take hours to cross and voices that carry nowhere

Find out how close it came to dying — telephones, the end of herding, and a generation who thought it was embarrassing

Find out what the Canarian government did in 1999 and why teaching it in schools was the thing that saved it

La Gomera is cut into deep ravines, so getting from one side of a valley to the other on foot takes hours while shouting across gets you nowhere. The islanders whistle instead — silbo gomero is Spanish rendered as whistled tones, and it carries up to five kilometres. It was widespread in the 17th century, and telephones and the collapse of herding nearly killed it: by the 1980s it was associated with rural poverty and people stopped teaching their children. The Canarian government made it a protected ethnographic heritage in 1999 and put it on the school curriculum, which is why it is still alive.

Silbo Gomero: The Language You Whistle

Walk into the laurel forest on a cloudy day, which is the weather it actually needs

Work out what you are standing in: a forest that covered Europe in the Tertiary and survives here and almost nowhere else

Find the difference between the true laurisilva and the drier fayal-brezal higher and more exposed

Look at the moss and epiphytes on the trunks and work out where the water is coming from — cloud, not rain

Climb to the Alto de Garajonay at 1,487 metres, the highest point of La Gomera, for the view of the cloud sea sitting on the island

Laurisilva — laurel forest — once covered almost the whole of Europe in the Tertiary, and then the ice ages killed it everywhere except a handful of Atlantic islands. Garajonay on La Gomera holds the best surviving example known in the Old World across 3,984 hectares, which is why it was made a national park on 25 March 1981 and listed by UNESCO in 1986. It works because the sea of cloud parks against the mountain and keeps the humidity almost constant with very little annual temperature swing. Close to fifty tree species grow in it, sorting themselves by ecology into true laurisilva and the drier fayal-brezal.

Garajonay: A Forest Left Over From the Tertiary

Book a permit — the descent runs on a capped daily quota and you will not get in without one

Walk the gorge down to the sea, about six hundred metres of descent between closing walls

Work out how you are getting out at the bottom, because there is no road

Look at the rock walls at the narrowest point and work out why the route was closed for years

Drive the Teno ridge road afterwards, which is an event in its own right

Masca is a hamlet on a knife-edge ridge in the Teno massif in north-west Tenerife, reached by a road of relentless hairpins, and from it a gorge drops about six hundred metres to the sea between walls that close in to a few metres wide. The walk down takes several hours over boulders and water, and you come out on a black beach with no road to it — historically you left by boat. The route was closed for years after deaths and rockfall and now runs on a booked, capped, helmeted basis with a fixed number of people a day.

Masca: The Gorge Down to the Sea

Swim in El Caletón, the natural pools in the 1706 lava where the harbour used to be

Find the fragments of the old port still visible under and among the lava

Work out what was lost: the main port of Tenerife, trading regularly with America, gone in one eruption

Find the castle of San Miguel, which survived the flow, and see how it sits relative to the old waterline

Walk the old town and work out how much of it was built on the wealth that stopped in 1706

A Genoese banker, Cristóbal de Ponte, founded Garachico and its harbour after the conquest of Tenerife in 1496, and through the 16th and 17th centuries it was the principal port of the island — regular trade with America and Europe ran through here. In 1706 the eruption of the Trevejo volcano buried most of the port. Only fragments of it are visible now. The town never recovered its position and is instead a quiet, handsome place with natural rock pools where the harbour used to be.

Garachico: The Port a Volcano Erased

Take the Teleférico del Teide cable car to 3555m and photograph the cloud layer below — on a clear night the neighbouring islands of La Palma, La Gomera and El Hierro are visible from the upper platform

Watch sunrise from the Roques de García volcanic formations on the Las Cañadas caldera floor — the lava geometry in pre-dawn light is one of the most extraordinary landscapes in the Atlantic

Visit the Observatorio del Teide on a public guided tour — the IAC observatory on Teide's flank is one of the best-equipped professional observatories accessible to the public in Europe

Drive the TF-21 road through the caldera to the Boca Tauce viewpoint at midnight and photograph the Milky Way above the Teide silhouette

Spain's highest mountain rises from the Atlantic above Tenerife in a UNESCO-protected caldera — El Teide holds Class 1 dark sky status, where professional astronomical observatories share the volcano's shoulder with a public cable car reaching 3555m

El Teide: A Cable Car to 3,555m and Stars Over the Caldera

Swim at the Lago Martiánez and work out that the whole complex is a César Manrique design

Work out why it was built: black sand, heavy Atlantic surf and a town that needed somewhere safe to swim

Go up to the Jardín Botánico, which was founded in 1788 to acclimatise tropical plants for Spain

Walk the old harbour and the fishermen's quarter, which predate the tourism entirely

Work out why the British came here in the 19th century and what they were coming for

Puerto de la Cruz was the first tourist town in the Canaries, receiving British visitors from the 19th century for the climate, long before the south of the island existed as a resort. Its north-coast beaches are black volcanic sand with heavy surf, which is why César Manrique was brought in to build the Lago Martiánez in the 1970s — a complex of seawater pools, islands and sculpture laid out over the shore, and one of the best things he did outside Lanzarote. The Jardín Botánico above the town dates from 1788.

Puerto de la Cruz: Where Canary Tourism Started

Come for Corpus Christi and see the sand carpet in the Plaza del Ayuntamiento before the procession crosses it

Work out where the material comes from: coloured volcanic sands carried down from the Cañadas del Teide

Walk the streets of flower-petal carpets, which are made by the neighbourhoods rather than the council

Go into the Casa de los Balcones and look at the Canarian pine woodwork

Work out that most of the Teide National Park is inside this municipality

La Orotava's historic centre was protected as a national ensemble in 1976 and is on the European Cultural Heritage inventory, and a large part of the Teide National Park falls inside the same municipality. For Corpus Christi the town covers its streets in carpets made of flower petals and, in the Plaza del Ayuntamiento, of coloured volcanic sand carried down from the Cañadas del Teide — a single enormous sand picture laid out by hand over days and walked over and destroyed in an afternoon.

La Orotava: Carpets Made of Volcanic Sand

Drive or ride up to the summit and look down on the cloud sea from above it

Work out why here and not simply anywhere high: laminar Atlantic air over open ocean with no turbulence, which is what gives stable light

Book a guided visit into the observatory and see the scale of the instruments

Stay after dark somewhere on the ridge and find out what a sky with a lighting law over it looks like

Walk a stretch of the crater rim path along the top of the Caldera de Taburiente

The Roque de los Muchachos is the top of La Palma, and the observatory on it exists because of a very specific combination: great height, and smooth laminar Atlantic air arriving over open ocean with no turbulence in it, which gives stable, clean light. That is a rarer condition than altitude alone and it is why some of the largest telescopes in the northern hemisphere are up here. The island protects it with a sky law limiting lighting, so what you see with your own eyes from the summit road is also extraordinary.