For one of its first forays into Barcelona's art scene, la Caixa bank converted modernist architect Puig i Cadafalch's Casarramona, a textile factory, into a state-of the-art gallery and added a modern entrance and a walkway to the main gallery by Japanese architect Arata Isozaki. The permanent collection of minimalist and abstract works includes a gargantuan mural by Sol LeWitt in the lobby, but it's the photography and contemporary art exhibits hosted in the first floor's three light-filled galleries that are really special.

Open Tuesdays through Sundays 10 am to 8 pm.

Located within what was the Casa de Caritat, a charitable institution for the city's poor during the reign of Charles IV, the CCCB in El Raval creates an interesting dialectic with the adjacent MACBA. In its 21st-century incarnation, by architects Piñón and Viaplana, it has become a multidisciplinary space, hosting music, dance, video, and theater sessions along with high-brow seminars on art and politics. In the summer, movies by some of Barcelona's most talented young filmmakers are projected onto a giant silver screen in the 19th-century courtyard. It is also the daytime headquarters of SÓNAR, Europe's largest multimedia, electronic music, and general mayhem festival (34-93-492-9180; www.sonar.es).

Like most of Barcelona's other museums, this structure in San Gervasi is as impressive as the collection within. Cool and airy, with slate water pools and acres of glass, it is dominated by a glittering chrome spiral staircase that cascades down six floors, offset by raw steel and lit by tangerine and fire-engine-red skylights. Once in the exhibition space proper, visitors encounter an array of interactive objects, such as dinosaur skeletons, ancient Buddhist prayer books, plasma balls, pendulums, stick insects, and scorpion fish. Don't miss the pièce de résistance—a cross-section of the Amazonian rain forest in a giant tank, complete with piranha fish and capybaras (the world's biggest rodent).

Closed Mondays.

Ribera, more commonly known as El Born in reference to its main axis, Passeig del Born, is a medieval-turned-trendy neighborhood near the city center. After the obligatory visits to the soaring, columned Santa Maria del Mar, the Museu Picasso, and the Passeig del Born (the site of public floggings and burnings during the Spanish Inquisition), you'll probably want to seek out the neighborhood's quieter spots—this area can be overwhelmed with tourists at times. The tranquil Plaça de les Olles is great for an alfresco lunch, while Carrer de L'Esparteria and Carrer Vidriera are lined with quirky boutiques. Also check out the adjacent neighborhood of Sant Pere, which is a bit edgier than trendy El Born. Like New York's Lower East Side or Hoxton in London's East End, San Pere retains its eclectic atmosphere while casually embracing a slower-paced gentrification.

In 1925, journalist Àngel Marsà described fetid El Raval (the slum) as a warren of thieves, prostitutes, and lowlifes; the (mostly deserved) reputation stuck until recently, when a flurry of private and public initiatives—spiffed-up parks, museums, restaurants, and fashionable boutiques—infused El Raval, which borders the Ramblas close to the waterfront, with new life. The lower swath, nearest the port, still attracts some fairly unsavory characters, although regular crackdowns by police and mushrooming gentrification help. First up, visit MACBA a modern art museum surrounded by the best of the barri's new streets and plazas (1 Plaça dels Angels; 34-93-412-0810). Then head south along the palm-filled boulevard of Rambla del Raval, where the ethnic Monraval market thrives on Saturdays. About halfway down, the cylinder-shaped Barceló Raval hotel stands loud and proud, while next door a new film theater is taking shape.

After an illustrious career in Le Corbusier's Paris studio and then as Harvard's dean of architecture, Josep Lluís Sert designed the Joan Miró museum in memory of his lifelong friend. It won the prestigious AIA Twenty-Five-Year Award in 2002 in recognition of a "design of enduring significance." And rightly so. An exceptional homage to light and space, the building's airy passages, high ceilings, soaring archways, and accompanying sculpture gardens compose a futuristic Nasrid palace in Parc de Montjuïc. It also holds the world's largest collection of Miró's work, some 11,000 pieces in all. There are sculptures and paintings (including Flame in Space and Nude Woman, and Woman and Bird), a few textiles and ceramics, an almost-complete set of his graphic works, and 8,000 drawings. Most were donated by Miró himself.

Closed Mondays.

This headland park to the southwest of the city welcomes more than 15 million visitors a year to its museums, concert arenas, sports centers, and gardens (only New York City's Central Park gets more foot traffic). Mossén Costa i Llobera is the best collection of its kind in Europe—a secret garden with a sea view, planted with more than 800 exotic species of cacti (Carretera de Miramar 1; 34-93-424-3809; www.bcn.es/parcsijardins/pa_llobera.htm). The Jardí Botànic, with its futuristic steel banks and hardwood walkways, was inaugurated in 1999. The planting pulls together vegetation from Mediterranean-like climates around the world, such as rapistrum rugosum—Texan bastard cabbage (34-93-289-0611; www.bcn.es/parcsijardins/pa_botanic.htm). Full maturation is still a ways off, but for keen gardeners and botanists, it's a fascinating amble.

Girona, Catalonia's second city, an hour's train journey from Barcelona, is fortified by stone ramparts along the banks of the Onyar River—walk along the walls for an excellent bird's-eye view of the city. In addition to smart boutiques, there's a warren of narrow, shady streets and cool courtyards in the medieval quarter, and the Girona cathedral has an 11th-century Charlemagne tower, a beautifully preserved Romanesque cloister, and the world's widest gothic nave. Before a hundred years of persecution (1391 to 1492), the city had a sizable Jewish community, and the Call (Jewish quarter) is one of the best preserved Jewish quarter's in Europe. The Centre Bonastruc ça Porta, home to the Museum of the History of the Jews, is at its center. Take a short taxi ride from town for lunch at the stylish new home of El Celler de Can Roca, a Michelin-starred showcase for some of the most talented cooking in the country.

Fiercely independent, Gràcia is a curious bed partner to the metropolis. Perched above the Eixample, this "village" was entirely separate from the city until the construction of the Passeig de Gràcia in 1897. With a distinctive atmosphere, organic markets, sunny plazas, and cute two-story houses, it retains its neo-radical character and continues to attract students and free spirits in droves (although middle-class residents come to escape the hurly-burly of the center as well). During the third week of August, it's also host to one of the city's most extravagant festivals, the Festa Major de Gràcia (34-93-459-30-80; www.festamajordegracia.cat).

The opulent Liceu was built in 1847 as a paean to the arts, with gilded ballrooms, a hall of mirrors, and an auditorium similar to Milan's Teatro alla Scala. It's suffered two fires over the years, the first in 1861 and the second in 1994, which ultimately hastened its leap into the 21st century; it's now one of the most technologically advanced theaters in the world. The Liceu hosts a program of events ranging from flamenco shows to ballets to classic operas. There's also a standard guided tour (daily at 10 a.m.) for a rundown of its history. But much more interesting is the new behind-the-scenes tour, which reveals the inner workings of the multilevel stage, the costume room, and the technical controls. Tours are given at 9:30 a.m. daily (call ahead in case productions get in the way), and you can reserve tickets in advance (34-93-485-9914). Season ticket holders take up the bulk of seats for most shows, but you can pick up what's left online, where full details of the season's shows are also listed. .

Through all Barcelona's self-styled reinvention, the pedestrian walkway known as La Rambla has remained the city's most enduring icon. Even if some locals shy away because of the many tourists, the broad sycamore-lined path stretching a mile from Plaça Catalunya to the harbor is a required visit. It's flanked by famous buildings like the Gran Teatre del Liceu and the atmospheric Café de l'Opera, and the tile mosaics embedded near the Boqueria market are by native son Joan Miró himself. Rambla means "stream" in Arabic, and the pedestrian-only thoroughfare actually used to be a riverbed. These days, it's full of life, with wacky street performers, preening local teenagers, and fútbol fans celebrating the latest Barça victory.

When Richard Meier's cool, white, futuristic "ship" sailed into the heart of El Raval, it regenerated an area best known as the underbelly of Barcelona. Inspired by Le Corbusier, the real art here is the building itself—straight lines and curves juxtaposed against a sapphire sky. A skylight-dotted roof floods the interior with natural light. The permanent collection, made up mainly of works from the second half of the 20th century, gives a good overview of the fundamental principles of contemporary art.

Closed Tuesdays.

In the 13th century, Catalonia was a powerhouse at sea, and many of the kingdom's ships were built in the mammoth Drassanes (Royal Shipyards) in Barcelona. The city's greatest civic medieval structure, the long-lined, elegant Drassanes now houses the Maritime Museum, a fascinating, kid-friendly place that explores Catalonia's seafaring history through reconstructions of ships and fishing boats, and interactive exhibits. The museum also has a seaside annex out by the port, which includes a three-masted schooner from 1918; you're free to roam.

Covering 1,000 years of Catalan art, this state-of-the-art museum on Montjuïc was carved out of the Palau Nacional for the International Exposition of 1929. It has now absorbed the Thyssen-Bornemisza collection (previously at the monastery in Pedralbes) and the works from the Museum of Modern Art (previously in the Parque Ciutadella). Set aside an entire afternoon to fully appreciate the sheer extent of the collection. The 11th-century Romanesque works constitute one of the best exhibits in the world and include some sizable original 13th-century ecclesiastical murals as well as some gruesome renditions of medieval and gothic paintings.

Closed Mondays.

It's a mere 20 minutes on the FCG train line from Plaça Catalunya, yet most visitors admire these nearly 20,000 acres of open space, Holm Oak forest, and farmland only from the plane. What everyone's missing is innumerable hiking and biking trails, a masia (Catalan farmhouse) lunch of hearty country fare—think barbecue chops and sausages, pa amb tomaquet (bread with tomato), and roasted vegetables—and a glass elevator ride and 360-degree views from the top of Norman Foster's 944-foot Torre de Collserola (Carretera de Vallvidrera al Tibidabo s/n; 34-93-406-93-54; www.torredecollserola.com).

The Penedès region, southwest of Barcelona, has been making wine since the Romans arrived 2,000 years ago. Its rolling hills are home to some of the biggest names in Spanish still and sparkling wine, such as Torres (www.torres.es), Codorniu (www.codorniu.com), and Freixenet (www.freixenet.com), all of which offer daily cellar tours. Though traditionally known for light, fruity whites and especially sparkling cava, gutsy vintners are earning praises for their balanced reds as well. The area is also gaining respect for boutique bottlings from such wineries as Jean Leon (www.jeanleon.es) and Albet i Noya, Spain's first organic winery (www.albetinoya.com).

Few visitors venture into Poble Sec, the largely residential "dry village" (it lacked any water supply until the 19th century), with narrow streets and 18th-century buildings that back up the east-facing side of Montjuïc (the mountain wedged between the city and the sea). There's not much in the way of sights—for years, the main draw was tapas at Quimet & Quimet. Yet slowly but surely, it's developing a reputation as a cozy neighborhood studded with clandestine bars and "members only" dinner clubs (you need only eat to join) such as Tapioles 53. You need only eat to join.

Poble Nou is flat, with wide boulevards and low-rise housing. Gentrification of this former industrial neighborhood has come in the form of Diagonal Mar, a gated residential community, and 22@, a dot-com business precinct, both of which have gobbled up a fair amount of Poble Nou's grittier charm. The area, however, has spawned a number of decent clubs and restaurants (most notably Razzmatazz and Oven), and a couple of the defunct factory buildings have been revived as art and design studios. This is also home to the city's other Ramblas—Rambla del Poble Nou—an infinitely more genial alternative to the rowdy Ramblas in town. Another Poble Nou landmark: French architect Jean Nouvel's gigantic, phallic Torre Agbar.

Less than 35 minutes away by train from Barcelona's Sants station, Sitges is a small, self-confident seaside town. It was "discovered" as a bohemian outpost in the latter part of the 19th century by the artist Santiago Rusiñol, who made it the darling of Barcelona's artistic classes when he moved his studio there and began throwing decadent parties. The feeling of bonhomie has survived to this day, and the town's whitewashed houses, pretty cobbled streets, ornate villas, and beaches attract a diverse crowd of gay partygoers, families, and hipsters. The most exciting times to visit are during carnival (early spring), the Festa Major (August), and a film festival that specializes in all things macabre (October). Ornately tiled, neogothic Cau Ferrat was built by Rusiñol to join his two cottages together and is now a popular museum (Carrer del Fonollar; 34-93-894-0364). Arrive early to beat the crowds.