Sakoneta, probably the 'grooviest' (and weirdest) beach in Spain

'WINDSWEPT' might be a way of describing one of Spain's oddest-looking beaches, or perhaps 'ploughed' – but the Sakoneta, as well as a photographer's and social media-user's dream, is also a geologist's paradise and a window on the world aeons before we as a species got here.

If beaches, for you, only hold any attraction where they're palm-fringed with velvety, golden sands, turquoise waters, parasols, kiosks, sunbeds, port-a-loos and foot-showers, this chunk of coast in Deva, Guipúzcoa province – of which the capital is San Sebastián – is unlikely to be on your travel bucket list; but if raw nature, Jurassic landscape and unique, one-off panoramas are your thing, this officially-protected Basque Country biosphere is very much worth the detour.

Known as 'Deba' in the regional language, euskera, the shores of the town sit between Haitzandi and Haitzabal and form part of the Deba-Zumaia bio-reserve, an eight-kilometre slice of cliffs that look as though they were turned out of a jelly-mould and then hit by a gale heading north before they were properly set. 

Rippled surface covered in heathland grass on the top, and barcode furrows on the ground, the rockface in the middle looks as though it had been sliced with a bread-knife.

It's hard to believe Sakoneta beach's design is pure accident.

Part of the northern Basque Country 'Flysch Route', the cove is perhaps one of the most striking examples along its length: Formed during the early Cretaceous era, after the end of the mass extinction that finished off the Jurassic period – so, about 100 million to 65 million years ago – the system runs from the Andutz fault, a 700-metre-thick plate of limestone and marl (calcite mudstone) strata interspersed with turbidite deposits.

These are the result of coarse-grained sediment dragged by underwater avalanches and dumped in deep ocean troughs beneath the continental shelves, which, when pulled ashore, give the landscape its 'groovy' texture. 

'Flysch' are rocky fascias made from sediment – the 'dregs' of the sea – alternating layers of hard material, like limestone, sandstone and slate, with soft material such as clay and marl; the end 'product' is a stripey surface in different shades of grey and beige, from almost charcoal and brown to almost white, and the appearance of its having been raked over.

You find yourself wanting to call it a 'lunar landscape', despite its lack of craters; it would certainly give another meaning to 'Moonraker'.

According to geologists who helped draft the 'official conservation' legislation protecting the Sakoneta from development, exploitation and mass tourism, the entire scene 'represents the start of a long period of tectonic calm', or when the continental plates stopped jiggling about and changing the shape of Eurasia, America and Africa; the Sakoneta beach was created by this restlessness in the earth's crust, and then it stopped, leaving behind what we have today all over Instagram.

Around 15 metres wide, there's plenty of space to set up a towel (it would have to be a padded one, because of the ruts) but the beach is only 40 metres long, so you'll have walked from end to end within seconds and found plenty of camera fodder even in that short time. The unusual 'patterns' and 'shapes' of the waves, caused by the uneven surface they break and flow onto, the whipped-cream cliff above it, and the array of amazing natural stone 'sculptures' – some of which look like broken chunks of Classical columns – mean these mere 40 metres contain a geographical treasure trove.

Well, turbidite sequences are known for being the number one venue type for gold-fossicking; just ask anyone from Ballarat (Australia, State of Victoria), so perhaps 'treasure trove' is an accurate description.

But you can't very well go digging in a protected bio-reserve, and in any case, if there had been tonnes of lode gold deposits off the Sakoneta, they would have been found long before now.

As a visitor hotspot for an extended day trip, the Sakoneta beach is, indeed, pure gold, very precious and of incalculable value.

Luckily, getting there is less hassle than trying to make your fortune from mining this highly-coveted and priced metal in a place where everyone else has the same idea: Take the N-634 highway and turn off for Errotaberri, between Itziar and Zumaia, head for the recreation and farm tourism centre in Errotaberri, and then pop your sturdy shoes on because you'll have a 15-minute hike ahead of you. Or turn off the N-634 towards the Itxaspe campsite and holiday park level with Itziar to get to the viewing point.

In Deba itself, a village of around 5,000 residents, you'll find plenty of sightseeing ideas, too – the Gothic-style Santa María church holds 'National Monument' status – and you'll probably find an organised excursion you can join to take you along the dramatic, unspoilt shores of the complete Flysch Route.