After explaining the finer points of the works of Paul Klee, Alberto Giacometti and Rene Magritte on the upper floors of Vienna's Museum of Modern Art, our enthusiastic young guide tried to prepare us for a cultural jolt as our elevator descended to the basement.

Awaiting us were the masterworks of Viennese Actionism, a movement that scandalized staid Vienna in the 1960s and 1970s. One artist, Hermann Nitsch, created a work by hanging a disemboweled lamb in front of a linen sheet splattered with blood. Mercifully, the original was long gone, but it was preserved in a series of photographs. In another creation, "Endurance Test," artist Gunter Brus performed various acts of self-mutilation while dressed in women's stockings and garters. Our guide assured us that the artists had something profound and significant to say.

Still, as we gazed at a video monitor showing artists painting the nude bodies of women, we were glad that our two children were across the street at a cafe.

The modern art museum is part of an extraordinary new complex in Vienna called the MuseumsQuartier Wien that is causing a stir in the art world.

We caught our first glimpse of the Museum Quarter as our tram rounded the bend near Museumsplatz, in the heart of the historic Austrian capital, during a trip to Central Europe in mid-March. We'd heard about Vienna's brash new art and cultural center -- and the many battles that surrounded its creation -- and were eager to see the upstart complex.

After only four years of operation, the Museum Quarter has become one of the world's 10 largest and most popular museum and exhibition venues, rivaling the likes of New York's Metropolitan Museum of Art and the Pompidou Center in Paris. One critic wrote that the cultural megaplex, with almost 650,000 square feet of space, has bridged the gap between the imperial relics of the Habsburgs and the edgy art movements that have emerged in Vienna in recent decades.

More than 2.6 million people flock to the MQ every year, securing Vienna's reputation as one of the cultural crossroads in Europe. The complex's director, Wolfgang Waldner, calls it a prime example of a "third place" -- a 21st-century hybrid of hangout and multi-sensory cultural experience. "The idea is to create places in the center of cities that are culturally charged," he told us in an interview. "People come because of the atmosphere."

Yet the peach-colored baroque facade of the former Habsburg imperial stables, across the street from the Maria Theresien Platz with its gargantuan art and natural history museums, gives little hint of what lies in the courtyards behind it.

The complex boasts two of Europe's newest and most important modern art museums -- the Museum of Modern Art (Moderner Kunst) and the Leopold Museum, which both opened in September 2001. The block-shaped Leopold, sheathed in gleaming white Bulgarian limestone, houses the the country's largest collection of Austrian masters of the late 19th and early 20th centuries, including Richard Gerstl, Gustav Klimt and Egon Schiele. The Museum of Modern Art, constructed with basalt lava and dominated by a 115-foot-high atrium, holds one of Europe's biggest collections of modern art, including the blood-splattered Viennese protest art.

It seems fitting that the MQ, which is as much a social and cultural oasis for artists and young people as a museum and exhibition center, has rhythms much different than its tradition-bound neighbors in this citadel of conservatism. Throughout the spring and summer, thousands of people gather every day and night at sidewalk cafes in the courtyard, including many who don't actually visit the major museums or the children's center, called Zoom-Kindermuseum. The vast majority of the visitors are locals, and many come back repeatedly, as we would, to soak up the atmosphere, if not the art exhibits.

"This is our big success -- that we created an island within a city," Waldner said. "It's an irony to hide it behind baroque walls, but it works."

For much of our stay in Vienna, we followed the path of first-time visitors -- beginning with a trip to see the famous but less-than-exciting Lipizzaner stallions in the magnificent Spanish Riding School. The riding school is part of the Hofburg, the winter palace of the Habsburgs, rulers of the Austro-Hungarian Empire until 1918.

Our daughter Alix, 16, and son Stephen, 11, got a kick out of the Haus der Musik, an interactive museum where we composed our own waltzes electronically and conducted -- virtually -- the Vienna Philharmonic on a big screen. The second violinist harangued us in German for our sub-par performances.

After that were quick tours of the beautifully refurbished Albertina Museum, which featured a special exhibit of Marc Chagall's Bible paintings, and the Schatzkammer, a Hofburg museum devoted to the valuables of the Imperial Treasury. We finished off our by-the-guidebook tour with the Schoenbrunn Palace, the Habsburgs' spectacular summer residence on the outskirts of the city. The palace has 1,400 rooms, but we toured only 22 -- including the Hall of Mirrors, where Mozart performed for royalty when he was 6, and the fabulous Grand Gallery.

By then, we were eager to turn our attention to the Museum Quarter, which turned out to be the perfect counterpoint to Vienna's more traditional offerings. Behind the walls -- designed by famed Viennese architect Johann Bernhard Fischer von Erlach in the early 1700s -- is a sprawling complex of modern and experimental museums; airplane- hangar-size exhibition halls for the annual Vienna Fair and contemporary shows and exhibits; the children's museum; and quartier21, a cultural cluster. It houses artists publishing magazines, producing neon art and rescuing long-forgotten Austrian pop music back to the 1950s. One tenant collects and displays computer keyboards as art; another is a mathematics professor who explores the relationship between math and art.

We started our day by peeking into the studios of Puls TV, an independent regional television news station that operates on the grounds, then spent some time watching young kids making pottery and exploring a mock archaeological dig at the Zoom-Kindermuseum.

Then it was on to the Leopold, the new home for the vast modern art collection of Viennese ophthalmologist Rudolf Leopold, which is now owned by Austria. The collection of well over 5,000 pieces includes a large number of paintings by path-breaking Viennese expressionist Schiele, who died at 28 during the 1918 flu epidemic, as well as works by Gustav Klimt -- although not "The Kiss," which is at the nearby Belvedere Palace.

The Leopold also contains important objects from the turn-of-the-19th-century Austrian arts and crafts movement as well as works of ancient Chinese and Japanese art.

During the 1970s, a debate raged over whether the site, which in recent years had been used for trade fairs and exhibitions, should be turned into a cultural center or a more commercial enterprise, such as a mall or hotel complex. Once that argument was settled, battles in the 1980s and 1990s centered on the size of the project. Critics, worried that the megacomplex would clash with nearby historic landmarks, forced repeated reductions in size and successfully barred efforts to build a tall column or tower that would have been visible from afar and become the symbol of the Museum Quarter.

At the same time, Vienna was becoming younger and fresher in its outlook, and more creative. Today, Waldner argues, the city is "more cutting edge than Berlin or Paris." The MQ complex, jointly owned by Austria and the City of Vienna, eventually opened in 2001, but the controversy didn't end. "Some folks still want this as only a museum-sanctioned art space," says Waldner. "We interpret culture much more broadly."

Even the "young lava" (anthracite-colored basalt) used for the exterior of the Museum of Modern Art is designed to convey a sense of freshness and vitality. The museum's collection of 5,500 works is built around a core of New Realism, Pop Art and Photorealism, and includes works by Picasso, Russian expressionist Wassily Kandinsky, Italian futurist Giacomo Balla and Dutch abstractionist Piet Mondrian. While we were there, the museum was featuring a show by John Baldessari, a California native and leader of the conceptual art movement who in 1970 burned all his paintings done between 1953 and 1966 to demonstrate his move to the dialogue between images and texts.

The most startling work, of course, is Viennese Actionism, billed as Austria's most important contribution to avant-garde artistic expression. These artists of the 1960s rejected traditional genres of painting, drawing and sculpture. Otto Muehl, for example, found expression in tearing apart, smashing and tying up materials. Gunter Brus used his own body and that of his wife, Ana, as the canvas for his paintings. Many of the artists freely used blood and excrement to make their points and break taboos.

The point of all these works is probably best summed up by one of the "text paintings" hanging in the exhibit that declares: "I Will Not Make Any More Boring Art."

Eric Pianin is the congressional editor of The Post. Laurie McGinley is an assistant Washington bureau chief for the Wall Street Journal.

Vienna's Museum Quarter: Art for adults, and kids' play at Zoom-Kindermuseum.The Leopold Museum is one of many art institutions and spaces in the Museum Quarter, a cultural complex in Vienna. The Museum Quarter in Vienna is more than just art; visitors hang out at the cafes and soak up the scene.