Gaudi remains the master of all that we survey

The speed of change in Barcelona is unsettling. So why does the work of one architect continue to dominate the landscape?

Building in Barcelona must be an elephant trap for any ambitious architect. This is Antoni Gaudi's turf – no other city is so readily associated with a single architect. Which leaves today's practitioners with an invidious choice – do you "do a Gaudi" and build a showstopper or, almost more ostentatiously, design something understated?

Ricardo Bofill's new terminal, barely out of its wrapping, at Barcelona's El Prat airport is not short on ambition; it is part of a masterplan to increase passenger capacity to more than 70 million a year. The vast complex looks thoroughly 21st century with acres of granite, aluminium and glass. It hums with efficiency and is, we are told, sustainable to the Nth degree. But where is the X factor?

Bofill's terminal will win few votes in a play-off against Richard Rogers' Stirling Prize-winning Terminal 4 in Madrid. Which is all the more surprising, given that Bofill is a native son of Gaudi's city.

He is also responsible for Barcelona's other new landmark: the unmissable sail-shaped W Hotel perched on the furthest reach of the city's harbour. Again the building seems surprisingly inhibited despite its size and presence. This time the comparison is with another great sail-shaped hotel, the Burj Al Arab in Dubai. And though I have seen the Burj only in photographs, it steals the show. Dubai's sail seems ready to set off to sea on the next gust of desert breeze, while Barcelona's is too heavy to move.

The view from within the hotel, though, compensates. Bedrooms facing north look on to the multiple crescents of beaches leading towards Port Olimpic – not quite Copacabana, but a quantum improvement on the derelict waterfront of just 20 years ago.

This is a city with more than its share of great viewpoints and the 26th floor of the W is a worthy addition. It is a gravity-defying platform from which the whole city opens up – but Gaudi himself would struggle to recognise the skyline.

The Hotel Arts and the Torre Mapfre, both built around the time of the 1992 Olympics, dominate the marina; panning left, you find French architect Jean Nouvel's Torre Agbar (the phallic building is known locally as The Suppository among other less repeatable nicknames), after which the eye is grateful for the familiar cluster of cranes that mark the perpetual construction at the Sagrada Familia.

Like Gaudi's grandiose, crazy church itself, the city seems perennially unconvinced that it is the finished article. The Olympics famously were harnessed to drive through the regeneration of the port area, and a similar, though less successful trick was pulled in 2004 with the lavishly budgeted Universal Forum of Cultures. The speed of change is unsettling, denying even regular visitors the comfort of familiarity.

It's not just the new additions that have changed the city. The celebrated Ramblas, the glorious boulevard that runs up from the port to Placa Catalunya, was ever a magnet for visitors, but under pressure from hugely increased traffic it has turned into a nowhere land of "living" statues, artless cartoonists and hopeless buskers. I try to make out the distinctive "eu" diphthong of spoken Catalan in the mêlée, but all I can hear through the background noise is the twang of cruise-ship Americans. For a mad moment, I am nostalgic for the bag snatchers and cutpurses of old – though the high-visibility policing suggests they are still here, lurking in the shadows.

The Born district, however, a few blocks to the north-east, retains much of its character. The knot of medieval streets around the church of Santa Maria del Mar is inhabited by a mix of blue-collar families and young coolerati. Even on a busy Saturday afternoon the Passeig del Born, next to the church, is free of living statues.

The area is in the grip of gentrification, with property prices on an upward curve. But humble barbershops, locksmiths and groceries can still to be found among some of the coolest designer emporia and bars in town. The Vila Viniteca, at Agullers 7, may resemble a corner shop at first sight, but it is no ordinary victualler. Between shelves groaning with yummy produce, the yummy mummies of the Born pick out the most select cuts of eye-wateringly expensive Iberico ham and tranches of manchego cheese. Life outside is earthier; washing flaps on lines from balconies above and garlic-loaded aromas of home-cooking drift down.

The vapours floating around the frantic kitchen of Commerc 24 restaurant, just up the road, are more rarefied. Quails' eggs, truffles, artichokes and foie gras are the style here. Comerc 24 is the fiefdom of Michelin-starred Carles Abellan, who learned his trade at El Bulli from the legendary Ferran Adria. So, my expectations are not exactly dibbling around in the shallow end. The restaurant itself is both austere and playful, openly contradicting itself. Exposed bricks, cast-iron columns, charcoal walls and waiters in monastic black are offset by carnival yellow and red highlights. The ascetic feel of the main dining area is undermined by the whimsy of a ceiling lighting fixture made from brass cymbals. Though undeniably elegant, this is a space that doesn't respect the rules.

Abellan, however, does not go for the coup de théâtre style of his mentor – his signature is more understated. The festival tasting menu is full of wonderful ingredients served with a quasi-religious respect for their integrity. Stand-out treats of the gastro marathon include the cod with artichoke "ice cream", drizzled with caramel and pine nuts and the melting "autumn sirloin" with wild mushrooms, sweet potato chips and sesame paste is a very good idea. Correction – sublime idea.

The chef is about to take up residence at the new Bravo restaurant in the W Hotel, though as yet it is open only for breakfast – the chocolate spread with croutons drenched in olive oil and salt seriously ups the ante for hotel breakfasts. The W also scores in-room with a truly exquisite bed – seductive and cosseting – that requires iron discipline to get out of. The floor-to-ceiling windows make the most of the stunning beach view and the luminous Mediterranean light.

Then the marketing angels of W go and spoil it somewhat by sprinkling daft little thoughts-of-the-day around the rooms; sample – "What is the big picture?" asks a coaster, before replying, "Close your eyes and see it." I saw it, and it was unnecessary.

A shuttle bus into the centre would be a much better gimmick – getting to the heart of the city in Placa Catalunya requires a 10-minute cab ride or a 40-minute walk. The Passeig de Gracia, running north-west from the square, is home to two of Gaudi's best known extravaganzas – La Pedrera and Casa Batllo. They have an extraordinary effect on their surroundings, reducing everything else to mere background as the eye adjusts to their hallucinatory impact.

Casa Batllo is a must do. The house is the most complete realisation of Gaudi's galloping imagination. In the entrance lobby, the scaly patterned walls and writhing grand staircase with vertebrae-like projections suggest the architect accepted no limits on what could be built. The inspiration of the lobby is marine, and climbing the stairs to the first floor is the domestic equivalent of riding a huge sea creature up from the depths towards light.

On the first floor, known as the Noble Floor, where the Batllo family entertained, it becomes clear that the lobby was only an overture. There are no straight lines; ceilings twist into whorls; wooden door surrounds are perforated with blobs of coloured glass and the living room wall is an extended wave-shaped sash window that can be raised, turning the entire room into a balcony. The pillars both inside and on the exterior façade have bone-like facet joints evoking some kind of animal. We are in the belly of a beast.

Though Gaudi refurbished the house rather than build it from scratch, every square inch bears his imprimatur. He anticipated Danish designer Arne Jacobsen's concept of "total design" by 50 years – like Jacobsen, Gaudi insisted on control-freaking every detail, down to the precise shape of the door handles.

It is at the top of the house that Gaudi's wildest dreaming takes form. The roof curves like a dinosaur spine; the skin made from vividly coloured smashed tiles is distinctly reptilian. A giant ceramic cross rises behind the lashing animal. Some interpreters have suggested that Gaudi intended the whole building to represent the story of St George and the Dragon.

But it is equally tempting to picture the architect on the roof, imposing the sinuous curves of his beast-building on the city he loved – as a challenge to the future:

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How to get there

British Airways (0844 493 0758; ba.com/Barcelona) offers three nights at the five-star W Barcelona from £418 per person, including return flights from Heathrow and B&B accommodation.