Catalan architect Antoni Gaudí’s Art Nouveau creations are speckled throughout the city. Start at the Sagrada Familia, his large (and still unfinished) Roman Catholic basilica in Eixample district, then head south on Passeig de Gràcia to the pearly, undulating stone facade of Casa Milà followed by the rainbow-roofed Casa Batlló, before walking down the tree-lined La Rambla to Palau Güell, a mansion with Willy Wonka-style chimneys.

Among the best things to do in Barcelona is to eat your way around the city’s oldest market: La Boqueria, which dates back as early as 1217. Between stalls selling olives, fish, fruit, spicy Catalan sausages and thighs of jamón, you’ll find counter tables that turn fresh market ingredients into pintxos (small snacks): try thin slices of pata negra ham served in paper cones, flame-charred calçot onions, chickpeas with black sausage, or fried egg topped with baby squid. For bites a little further from the tourist crowd, head to the Santa Caterina and Sant Antoni markets instead.

Barcelona’s holy sites are diverse and impressive beyond Gaudi’s boundary-pushing Sagrada Familia. Worth visiting is the city’s Gothic cathedral, dedicated to the city’s patron saint, Eulalia; and Santa Maria del Mar, a 14th-century church built for the sailors, dock workers, fishermen and merchants that resided in La Ribera district, which was then right on the waterfront.

The Unesco World Heritage-listed Sant Pau was designed by Lluís Domènech, one of Catalonia’s leading modernist architects. The complex’s red-brick pavilions are a triumph of Art Nouveau architecture: this top Barcelona attraction housed a hospital from 1930 until 2009. Now it’s a museum and monument to the architect’s work - inside you’ll find pastel tiles, stunning stained-glass windows and labyrinthine tunnels.

Wandering through Barcelona’s shaded streets is certainly charming, but the Catalan capital looks just as good from on high. Gaudi’s Parc Güell was completed in 1914: it’s a testament to his rich, organic style, but it’s also full of political and religious iconography, as well as plentiful references to mythology, history and philosophy throughout. The Parc Güell is one of the best places to visit in Barcelona, and if you can tear your eyes from the vibrant architecture, you’ll see stunning views out over the city to the Mediterranean beyond.

Come to the Palau de la Musica Catalana for the music; stay for the architecture. Barcelona’s magnificent modernist concert hall was designed by Lluís Domènech for the city’s great and good. It’s opulently decorated in a style that merges Spanish-Arabic features with Art Nouveau – including a particularly beautiful stained glass ceiling in the centre of the hall.

When it comes to Barcelona’s attractions, don’t miss the art scene. The Joan Miro Foundation (whose basement hides the little-known Espai 13) and the Picasso Museum are the two must-sees, but you’ll also find ground-breaking galleries across the city. Make time for the IDEAL centre for digital arts, the Barcelona Museum of Contemporary Art and the grand Museu Nacional d’Art de Catalunya.

When you’re sipping vermouth in a Catalan tapas bar on a winding street, it’s easy to forget there’s a beach in Barcelona at all. But the sun, sea and sand are what give the city its laid-back energy. Come for a dip in the day and haggle with sarong-sellers who walk up and down the busy stretches of sand, then stop for a sangria and snack at a beachside chiringuito bar as you watch the sun set.

Barcelona is a walkable city, but it’s also very diverse, with each neighbourhood channelling a different vibe. Start in the historic streets of the Gothic Quarter for a taste of the city’s earliest days before exploring multicultural El Raval next door, home to hip bars and cool boutiques. Meanwhile, beachside La Barceloneta is fun and touristy – but check out its neighbour El Poblenou to see how the city’s hipsters spend their days.

A mere half an hour south of Barcelona by train are the cobblestoned streets of Sitges, fringed with potted flowers and whitewashed villas. Unlike the boisterous beaches of Barcelona, the coast here is dominated by locals, who spread out across the town’s 17 sandy beaches. When you’re done with the sun, head inland to the beautiful vineyards of Penedès for evenings spent sipping sparkling Spanish cava.