There was a time when the future of architecture was leisure. Cheaper travel, more spare time, longer holidays, easier foreign exchange: the new utopia of the 1960s would be a landscape of mega-hotels with pools, towers with balconies, pedestrianised streets with endless opportunities for dining, drinking and dancing, all executed in the crisp, clean architecture of international Modernism with views out to the endless blue of the sea. And all this would emerge from nothing.

Well, almost nothing. Miami laid the template, a city built on the Everglades. Its raison d’être was development, its industry was real estate, draining the swamp to create more of itself to be sold on.

Europe’s ground zero was Benidorm, Spain. On more solid terrain than Miami and with a long history of habitation as a fishing village, it became a remarkable experiment in creating a vertical city on the sea. Without Benidorm, perhaps there would be no Dubai — another city founded on the sand and forged through its skyline.

Benidorm has the most high-rises per capita of any town in the world. But the holiday resort is also almost universally derided as a mass-market metropolis aimed at boozy British crowds, a neon-lit strip advertising fish and chips, jelly shots and sangria pitchers.

Mediterranean architecture normally conjures images of elegant white villas on rocky outcrops or apartments with green shutters and gently peeling ochre plaster — not space-age towers with British-themed pubs stuffed into their bottoms.

It might not be the height of sophistication. But as an architectural experiment, it remains as intriguing and compelling as it was when it was conceived in the mid-20th century. It is a model of density that has not only endured but proved incredibly influential, and yet almost uncredited — probably because of snobbery. It is just not on the cultural radar in that way.

Modern Benidorm was created by its mayor, Pedro Zaragoza Orts (1922-2008), a local and an official in the Franco regime who was sent back from Madrid to become the mayor of his home city at the age of 28 in 1950. Benidorm’s fishing industry was ailing and southern Spain’s economy was still largely agricultural, but Zaragoza perceived a future in tourism. He dispensed with building height restrictions, which precluded towers, and welcomed bikinis (otherwise forbidden in strictly Catholic Franco-era Spain).

More towers, more flesh, more tolerance all round. Even with a grid plan on a US model this was nevertheless a distinctly European city, with walkable block sizes, the beach as its main public space, many pedestrianised streets and small, family-owned and run shops and bars.

While a traditional Spanish city would have featured plazas, public spaces of representation and relaxation, here they were replaced by hotel pools. These are semi-public spaces that create the dynamics. Viewed from balconies, restaurants and rooftops, they provide refreshing highlights in the streetscape, glimpses of sparkling blue always present to remind the visitor this is a pure vacation town, a land of leisure.

Benidorm’s designers had obviously been looking to American resorts such as Las Vegas, Miami, Mexico and even Cuba for inspiration. The towers were stunningly modern for a country in which architecture had been stuck in a conservative culture (with a few, brilliant exceptions such as Miguel Fisac).

Set against the striking background of the Puig Campana mountains, the towers were less disruptive than if they had been set into a flat landscape; the skyline asserted itself against the topography, as in Hong Kong. There were no architectural stars in Benidorm — no famous names or global firms — yet many of the towers are inventive, elegant, occasionally minimal, occasionally maximal, sometimes space-age and often pleasingly louche.

In a city built entirely by private concerns, one developer, Coblanca, exerted the largest impact. The architect it employed, Juan Guardiola Gaya (1927-2005), became the most influential single figure in shaping Benidorm’s skyline.

A Catalan, Gaya moved to Alicante in 1959. He designed more than 40 towers in the town and more than 100 in the region. From the 29-storey Torre Coblanca, Benidorm’s first high-rise (1966), to the incredible 26-storey Torre de Benidorm (1975), his buildings spanned the sleek international style to the expressive late Modernism that has recently been revived by practices including Herzog & de Meuron and OMA.

Look, for instance, at the formal similarity between Torre de Benidorm and Herzog & de Meuron’s 56 Leonard Street in New York. Coblanca 5 (1972) is a bundle of brick rods with curving bays whose form has been adapted and adopted by designers across the world.

Gaya was the Renaissance man of the region. He also designed the interiors, lobbies and sometimes the vivid murals, abstract sculptures and art that decorated them. At their best they are wonderful examples of a total Modernist vision. Despite the frenetic pace of change in the shops, bars and clubs on the street, many of the lobbies remain exquisitely untouched and his work can still be seen inside.

A number of Benidorm’s buildings feature theatrical sweeps, broad curves or chevron-shaped plans. Coblanca 3, with its first-floor pool and concave facade, brings to mind Oscar Niemeyer’s seductive Edifício Copan in São Paulo.

Although I don’t know its designer, I’m also very taken with the tower looming above Tony Roma’s steakhouse on the Avenida del Mediterráneo, slightly sinister with curved corners and curious, eye-shaped openings.

The density of this high-rise resort means elevations are as critical as the layout of the streets. It is rich, complex and colourful. Almost all buildings feature grids of balconies that give them texture, reinforced by bright awnings. Although many are now non-functional or shabby, the interplay of lowered, half-lowered and raised fabrics gives a wonderful, varied richness to the towers in striking palettes; canary yellows, tree-canopy greens and so on.

The building boom carried on into the 1980s but slowly gave way to a more globalised aesthetic, with towers such as the recently completed 47-storey Intempo, which would be equally at home in Shanghai or Dubai.

The last of the truly stylish, late modern towers is the Neguri Gane (designed by Roberto Pérez-Guerras and Julio Pérez Gegundez). It was completed in 2002 but looks like a Brutalist throwback, with an affinity to Madrid’s 1961 Torres Blancas. It also, arguably, predicted the form of Dubai’s Burj Khalifa.

The stereotype of Benidorm’s tourists is one of lobster-pink beer guts and screeching bachelorettes. Photographer Martin Parr’s photos have fixed an image of those Brits lolling by the pool and rolling through the streets against the abstract backdrop of the towers. The town’s appearances in popular culture have done it few favours. But this remains a classist, patronising image.

As much of the world is being careless with its best 1960s and 1970s architecture, redeveloping it for greater density and profit, Benidorm still revels in it. Those buildings have recently begun to be depicted in very different ways. Filtering out the tourists, photographers Roberto Alcaraz Oviedo and Al Mefer have found striking beauty in the skyline, divining pastel planes and surfaces of apparently endless balconies that sit somewhere between Andreas Gursky, JG Ballard and Wes Anderson.

Benidorm is not a beautiful place. Wandering around its landscape ofBritish-themed pubs (themselves modelled after British-themed British pub chains), tiki bars, sub-Vegas neons and English caffs can be a dislocating, occasionally unsettling, experience.

Yet there are glimpses of the town’s incredible architecture and design through the oddest apartment doorways, across pools and from balconies.It luxuriates in its reinterpretations of modernity. The towers are a rare survival of the optimistic architecture of a future of leisure, which, perhaps, we never quite caught up with.

Edwin Heathcote is the FT’s architecture and design critic

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