If you haven’t been to Valencia recently, you’re missing a trick. Spain’s third city has undergone a cultural renaissance on a scale not seen in the country since Gaudi got his hands on Barcelona. It has turned this once dusty port into the most exciting town on the Mediterranean.

Your first indication that the wild little sister to haughty Madrid and flirty Barcelona has reached the age of consent comes as you drive in from the airport, following the canalised course of the rerouted River Turia. The reinforced levee, like concrete anywhere in the world, is covered in graffiti, but instead of the usual witless scrawls, these huge, intricately painted messages are of love, the names of girls clasped by angels, entwined in roses and washed with tears.

It’s a good sign, and indicative of a city that has clearly fallen in love with itself. Like a gawky teenager transformed into a grown-up temptress, Valencia has slapped on the lipstick, hitched up her skirt and gone looking for holiday romance.

The old town is Valencia’s passionate heart, an enchanting warren of baroque’n’roll extravagance typified by the throbbing Barrio del Carmen. Valencianos are a nocturnal species – the city’s emblem is the bat – and here la marcha, the nightlife, is the best in Spain. Which means it’s the best in Europe, and probably the world.

Running alongside the urban jungle are the Jardines del Turia, a gorgeous green ribbon on the old course of the river. This five-mile stretch of orange groves, fountains and playgrounds terminates in the futuristic fantasy of Santiago Calatrava’s City of Arts and Sciences, rather modestly described by the architect as “an ensemble comprising a science museum, a planetarium and an opera house”, which lies scattered across the wide riverbed like the bleached bones of fallen Titans.

But the city’s charm becomes irresistible at the seaside. For years, Valencia turned its back on the sea, and the waterfront and fabulous beaches became increasingly shabby. Then the America’s Cup came to town, sparking a stunning transformation of the run-down port into a new marina city called Port America’s Cup. “The redevelopment has had an effect greater than the sum of its parts,” says Jordi Gauxa, a local journalist. “It has made the city complete.”

And about time too. The centrepiece of the marina is the America’s Cup Pavilion, a dazzling white concrete, steel and glass homage to the elegance of ocean racing. Designed by the British architect David Chipperfield, the building eschews the organic mystery of Calatrava in favour of clean layers and polarised light and shade, like some cubist collaboration between Tate & Lyle and NCP.

Here’s our timetable for the perfect Valencian day. There are just two rules to remember: first, never eat paella at night; second, never go out before 10pm. Abide by these and Valencia will love you as fiercely as you’re going to love her.

Morning: get up early and take a leisurely bike ride (www.valenciabikes.com) through the gorgeously perfumed Jardines de Turia to visit the City of Arts and Sciences while the light is at its best. Then stock up on arroz, sobresada and jamon at the Mercado Central, Valencia’s vast, kaleidoscopic covered market.

With the shopping in the bag, go and find the Holy Grail. It’s in a side chapel at the Catedral de Santa Maria de Valencia, on Plaza de la Reina, a five-minute stroll from the market.

Lunch:m paella, anyone? Tourists flock to La Pepica (00 34-963 710366, www.lapepica.com ), on Paseo de Neptuno, but only because it’s yet another stop on the endless Hemingway trail. Far better is the chicken-and-rabbit blend at nearby L’Estimat (963 711018); or the tiny Tasca Angel, on Calle Purisima, in the old city. The family make one pan of paella a day, and when it’s gone – which is rapidamente – it’s gone. Now what? A la playa. Choose from a £2 sun bed and a Cornetto on Las Arenas beach, or a sofa and a smoothie at the Valencian branch of that Ibizan chillout icon Café del Mar, on Playa de la Malvarrosa.

And tonight? Remember that if you go out before 10pm, it’ll just be you and the tumbleweed blowing through town. For dinner, try Casa Montaña (Calle Jose Benlliure 69; 963 672314, www.emilianobodega.com), for hearty platos tipicos at about £20 a head. For the big night out, book a table at Ca’ Sento (Calle Mendez Nuñez 17; 963 301775), where Raul Alexandre, who trained at El Bulli, deconstructs the old favourites while his mum, Mari, puts them back together again; £50 a head. Or try the superb £28 tasting menu at the avant-garde Seu Xerea (Calle del Conde de Almodovar 4; 963 924000, www.seuxerea.com ).

After dinner, a drink: spoken like a local. Kick off with a jug of agua de Valencia, a deceptively potent mix of cava, orange juice and brandy, at Café Madrid (Calle Abadia de San Martin 10). Bars never get going before midnight, and the best are concentrated in Barrio del Carmen. Try the stupendously baroque Café de las Horas (Calle del Conde de Almodovar 1); San Jaime (Calle Caballeros 51), in a converted chemist’s shop; or the arty Radio City (Calle Santa Teresa 19).

I feel like dancing: at La Indiana (Calle San Vincente 95), sharks swim in tanks on the dancefloor. The vast and friendly Las Dockas (Calle Doctor Marcos Sopena 52), down on the harbour, has a huge rooftop terrace and music that doesn’t stop until brunchtime.

I feel like dying: at club chucking-out time – 8am – Valencianos have a secret chillout spot, the Iglesia del Patriarca (Calle de la Nave 3). Here, in quite possibly the only church in the world boasting a stuffed crocodile, clubbed-to-death locals are resurrected by a spectacular Holy Mass, complete with chanting, smoke and a disappearing altarpiece. Getting there: there are nonstop flights to Valencia from 10 UK airports, and Dublin, with Clickair (00 800 2542 5247, www.clickair.com ); EasyJet (www.easyjet.com ); Jet2 (0871 226 1737, www.jet2.com ); Ryanair (0871 246 0000, www.ryanair.com ); and Thomsonfly (0870 190 0737, www.thomsonfly.com ).

Where to stay: the Neptuno (00 34-963 567777, www.hotelneptunovalencia.com ; doubles from £105) is the first hotel to be opened in Port America’s Cup, and is as close as you can get to the marina without sleeping on someone’s deck. Rooms are compact, but the gorgeous views from the rooftop hot tub offer ample compensation.

Options in town include the HT Petit Palace Bristol (963 945100, www.hthoteles.com ; doubles from £60), a minimalist pearl behind a 19th-century facade near the heart of the old city; and Hostal Antigua Morellana (963 915773, www.hostalam.com ; doubles from £32), around the corner from one of Valencia’s prettiest squares.

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